Department of Microelectronics
Faculty of Electrical Engineering, Mathematics, and Computer Science

dr.ir. G. de Graaf

Guest
Bioelectronics (BE), Department of Microelectronics

Expertise: Microsystems for gas sensing, optical spectrometry and precision circuits for readout. Micromachining and microfabrication technology in general. COMSOL. Tanner Tools (LEdit), TFCalc, MacLeod (thin film optics).

Biography

Ger de Graaf was born a long time ago in Delft. He has been a staff member at the Electronic Instrumentation Laboratory of the Faculty of Electrical Engineering at Delft University of Technology since 1976.

He received his BSEE degree in Electrical and Control Engineering with honours from the Technische Hogeschool in Rotterdam in 1983. His graduation project was on the damping of piezo-electric accelerometers by active feedback, supported by Bruel&Kjaer. From 1992 to 1996 he was a system manager and also owned a part-time consultancy company specializing in computer controlled measurement systems, working on an automated system for the energy measurement of heating systems in apartment buildings.

He has worked on the design of circuits for optical sensors in bipolar and CMOS technology. After this he started working on MEMS, mainly on infrared sensors and capacitive accelerometers and mixed-mode CMOS signal processing circuits for these devices. Around 2003 he started his PhD project on infrared optical systems and in 2008 he received his Ph.D. Degree from Delft University with the dissertation "Mid-Infrared Microspectrometer Systems". He is a (co-)author of around 130 scientific publications and main author of around 30 international scientific papers since 1988. He is a member of the IEEE and holds one patent.He was a project leader in an STW project on sensors for natural and combustible gas and participates in the national EDGaR gas research project.

Teaching

Currently I am a tutor and mentor for two groups in the first year student lab projects. At present I work on IC compatible gas sensors for gas sensing, impedance spectroscopy and optical spectroscopy for biomedical applications.

Projects history

CMOS-Compatible Hot-Wire CO2 Sensors

In the project, we have developed CMOS-compatible CO2 sensors that detect the CO2-dependent heat loss of a suspended hot-wire transducer using dedicated precision readout electronics.

  1. Standardizing designed and emergent quantitative features in microphysiological systems
    D. Nahon; R. Moerkens; H. Aydogmus; B. Lendemeijer; A. Martínez-Silgado; J. Stein; M. Dostanic; J.-P. Frimat; C. Gontan; M. de Graaf; M. Hu; D. Kasi; L. Koch; K. Le; S. Lim; H. Middelkamp; J. Mooiweer; P. Motreuil-Ragot; E. Niggl; C. Pleguezuelos; J. Puschhof; N. Revyn; J. Rivera; J. Slager; L. Windt; M. Zakharova; B. van Meer; V. Orlova; F. de Vrij; S. Withoff; M. Mastrangeli; A. van der Meer; C. L. Mummery;
    Nature Biomedical Engineering,
    Volume 8, pp. 941-962, 2024. DOI: 10.1038/s41551-024-01236-0

  2. Simultaneous detection of oxygen tension and pH for organ health monitoring during transplants
    Avik Sett; Robbert Friendwijk; Shaogang Wang; Ger de Graaf; Massimo Mastrangeli; Paddy French;
    In Peoceeding MNE 2024,
    2024.

  3. Opto-chemical pH detection of Myocardial Ischaemia using Fluorescent Hydrogels
    Ger de Graaf; Maurits Frans Vriesendorp; Amin Hassan; Patrick James French;
    IEEE Sensors Journal,
    Volume 22, Issue 11, pp. 10901-10909, June 2022. DOI: doi: 10.1109/JSEN.2022.3166709
    Keywords: ... Fluorescence, ischaemia, hydrogel, optical pH probe, HPTS, pyranine, fluorescent dye, dual wavelength excitation, ratiometric detection.

    Abstract: ... In this research fluorescent optochemical pH probes for the detection of ischaemia have been investigated. Myocardial ischaemia is the most prominent risk during heart surgery. During open heart surgery the heart is temporarily arrested and, since there no blood flowing, oxygen supply and removal of waste products is stopped and heart cells can be damaged. In this paper we propose a novel method to monitor the condition of the heart by placing optochemical pH sensors on several strategic places around the heart during surgery. Low cost opto-chemical pH sensors, using a HPTS (8-hydroxy-1,3,6-pyrene trisulfonic acid trisodium salt) fluorescent dye encapsulated in a thin bio-compatible hydrogel layer, were investigated for this application. Our research started with an extensive optical characterization of several types of hydrogel layers at different pH levels. Secondly a reflection probe prototype using several of these layers was designed, built and tested. Dual wavelength excitation and ratiometric detection of the fluorescent signals was used to detect the pH level. Typical output signals of 35% to 53% per pH in the range from 6.5-8.0 pH have been measured and a response time of typically 400 seconds was obtained for the prototypes. Finally based on our measurements on the HPTS layers and the reflection probe we propose an improved type of pH probe for the detection of ischaemia during open heart surgery.

  4. Rapid Prototyping of Organ-on-a-Chip Devices Using Maskless Photolithography
    Dhanesh G. Kasi; Mees N. S. de Graaf; Paul A. Motreuil-Ragot; Jean-Phillipe M. S. Frimat; Michel D. Ferrari; Pasqualina M. Sarro; Massimo Mastrangeli; Arn M. J. M. van den Maagdenberg; Christine L. Mummery; Valeria V. Orlova;
    Micromachines,
    Volume 13, pp. 49, 2022. DOI: 10.3390/mi13010049

  5. Heart Rate Extraction in a Headphone Using Infrared Thermometry
    Ger de Graaf; Daniel Kuratomi Cruz; Jaap Haartsen; Frank Hooijschuur; Paddy French;
    IEEE Transactions on Biomedical Circuits and Systems,
    pp. 1--1, July 2019. DOI: 10.1109/tbcas.2019.2930312
    Abstract: ... In this work we have analyzed, built and tested a novel system that uses infrared differential thermometry to detect the heart rate in the auricle. The sensor system was fitted into a commercial headphone since this work is a first step into integration of the system in a Bluetooth headset. Infrared thermography is a non-contact technique with improved user comfort and low power consumption. Positive results have been obtained after extraction of the frequency features of the bioheat transfer signal on test persons in rest. The heart rate is a vital indicator of the health state of an individual. By continuously monitoring it, the fitness and health of the cardiovascular system of a user can be analyzed and impending problematic health episodes could be addressed better.

  6. HEART RATE EXTRACTION IN A HEADPHONE USING INFRARED THERMOMETRY
    G. de Graaf; D. Kuratomi Cruz; J. Haartsen; F. Hooijschuur; P. French;
    IEEE Transactions on Biomedical Circuits and Systems.,
    Volume 13, Issue 5, pp. 1052-1062, 10 2019. DOI: 10.1109/TBCAS.2019.2930312
    Keywords: ... IR Sensor, heart rate, ear piece.

    Abstract: ... The heart rate is a vital indicator of the health state of an individual. By continuously monitoring it, the fitness and health of the cardiovascular system of a user can be analyzed and impending problematic health episodes could be addressed better. Existing techniques to measure heart rate, such as electrocardiogram or photoplethysmography, are either uncomfortable for the user, or are not low-power or sensitive to motion artifacts. Infrared thermography is a non-contact technique with improved user comfort and low power consumption. In this paper, we have analyzed, built, and tested a novel system that uses infrared differential thermometry to detect the heart rate in the auricle. The sensor system was fitted into a commercial headphone since this paper is a first step into integration of the system in a Bluetooth headset. To the best of our knowledge, there has been no previous work on the detection of the heart rate signal in the ear using infrared thermometry. Positive results have been obtained after extraction of the frequency features of the bioheat transfer signal on test persons in rest.

  7. CMOS-Compatible Carbon Dioxide Sensors
    Cai, Zeyu; van Veldhoven, Robert; Suy, Hilco; de Graaf, Ger; Makinwa, Kofi A. A.; Pertijs, Michiel;
    Makinwa, Kofi A. A.; Baschirotto, Andrea; Harpe, Pieter (Ed.);
    Cham: Springer International Publishing, , pp. 199--219, 2019. DOI: 10.1007/978-3-319-97870-3_11
    Abstract: ... This chapter presents two cost-effective sensors that measure ambient carbon dioxide (CO2) concentration, intended for application in smart ventilation systems in buildings or in mobile devices. Both sensors employ a suspended hot-wire transducer to detect the CO2-dependent thermal conductivity (TC) of the ambient air. The resistive transducer is realized in the VIA layer of a standard CMOS process using a single etch step. The first sensor determines the transducer's CO2-dependent thermal resistance to the surrounding air by measuring its steady-state temperature rise and power dissipation. A ratiometric measurement is realized by employing an identical but capped transducer as a reference. An incremental delta-sigma ADC digitizes the temperature and power ratios of the transducers, from which the ratio of the thermal resistances is calculated. The second sensor is based on a transient measurement of the CO2-dependent thermal time constant of the transducer. The readout circuit periodically heats up the transducer and uses a phase-domain delta-sigma modulator to digitize the CO2-dependent phase shift of the resulting temperature transients. Compared to the ratiometric steady-state measurement, this approach significantly reduces the measurement time and improves the energy efficiency, resulting in a state-of-the-art CO2 resolution of 94 ppm at an energy consumption of 12 mJ per measurement.

  8. A Phase-Domain Readout Circuit for a CMOS-Compatible Hot-Wire CO$_2$ Sensor
    Z. Cai; R. van Veldhoven; H. Suy; G. de Graaf; K. Makinwa; M. Pertijs;
    IEEE Journal of Solid-State Circuits,
    Volume 53, Issue 11, pp. 3303--3313, November 2018. DOI: 10.1109/JSSC.2018.2866374
    Abstract: ... This paper presents a readout circuit for a carbon dioxide (CO2) sensor that measures the CO2-dependent thermal time constant of a hot-wire transducer. The readout circuit periodically heats up the transducer and uses a phase-domain modulator to digitize the phase shift of the resulting temperature transients. A single resistive transducer is used both as a heater and as a temperature sensor, thus greatly simplifying its fabrication. To extract the transducer’s resistance, and hence its temperature, in the presence of large heating currents, a pair of transducers is configured as a differentially driven bridge. The transducers and the readout circuit have been implemented in a standard 0.16-μm CMOS technology, with an active area of 0.3 and 3.14 mm2, respectively. The sensor consumes 6.8 mW from a 1.8-V supply, of which 6.3 mW is dissipated in the transducers. A resolution of 94-ppm CO2 is achieved in a 1.8-s measurement time, which corresponds to an energy consumption of 12 mJ per measurement, >10× less than prior CO2 sensors in CMOS technology.

  9. A real-time reconfigurable architecture for large-scale biophysically-accurate neuron simulation
    A. Zjajo; J. Hofmann; G.J. Christiaanse; M. van Eijk; G. Smaragdos; C. Strydis; A. de Graaf; C. Galuzzi; R. van Leuken;
    IEEE Transactions on Biomedical Circuits and Systems,
    Volume 12, Issue 2, pp. 326-337, 2018. DOI: 10.1109/TBCAS.2017.2780287
    document

  10. A Phase-Domain Readout Circuit for a CMOS-Compatible Hot-Wire CO2 Sensor
    Z. Cai; R. van Veldhoven; H. Suy; G. de Graaf; K. Makinwa; M. Pertijs;
    IEEE Journal of Solid-State Circuits,
    Volume 53, Issue 11, pp. 3303--3313, November 2018. DOI: 10.1109/JSSC.2018.2866374
    Abstract: ... This paper presents a readout circuit for a carbon dioxide (CO2) sensor that measures the CO2-dependent thermal time constant of a hot-wire transducer. The readout circuit periodically heats up the transducer and uses a phase-domain modulator to digitize the phase shift of the resulting temperature transients. A single resistive transducer is used both as a heater and as a temperature sensor, thus greatly simplifying its fabrication. To extract the transducer’s resistance, and hence its temperature, in the presence of large heating currents, a pair of transducers is configured as a differentially driven bridge. The transducers and the readout circuit have been implemented in a standard 0.16-μm CMOS technology, with an active area of 0.3 and 3.14 mm2, respectively. The sensor consumes 6.8 mW from a 1.8-V supply, of which 6.3 mW is dissipated in the transducers. A resolution of 94-ppm CO2 is achieved in a 1.8-s measurement time, which corresponds to an energy consumption of 12 mJ per measurement, >10× less than prior CO2 sensors in CMOS technology.

  11. CMOS-Compatible Carbon Dioxide Sensors
    Z. Cai; R. van Veldhoven; H. Suy; G. de Graaf; K. A. A. Makinwa; M. Pertijs;
    In Low-Power Analog Techniques, Sensors for Mobile Devices, and Energy Efficient Amplifiers,
    Springer Science \& Business Media, November 2018. DOI: 10.1007/978-3-319-97870-3
    Abstract: ... This chapter presents two cost-effective sensors that measure ambient carbon dioxide (CO2) concentration, intended for application in smart ventilation systems in buildings or in mobile devices. Both sensors employ a suspended hot-wire transducer to detect the CO2-dependent thermal conductivity (TC) of the ambient air. The resistive transducer is realized in the VIA layer of a standard CMOS process using a single etch step. The first sensor determines the transducer’s CO2-dependent thermal resistance to the surrounding air by measuring its steady-state temperature rise and power dissipation. A ratiometric measurement is realized by employing an identical but capped transducer as a reference. An incremental delta-sigma ADC digitizes the temperature and power ratios of the transducers, from which the ratio of the thermal resistances is calculated. The second sensor is based on a transient measurement of the CO2-dependent thermal time constant of the transducer. The readout circuit periodically heats up the transducer and uses a phase-domain delta-sigma modulator to digitize the CO2-dependent phase shift of the resulting temperature transients. Compared to the ratiometric steady-state measurement, this approach significantly reduces the measurement time and improves the energy efficiency, resulting in a state-of-the art CO2 resolution of 94 ppm at an energy consumption of 12 mJ per measurement.

    document

  12. A Phase-Domain Readout Circuit for a CMOS Compatible Thermal-Conductivity-Based Carbon Dioxide Sensor
    Z. Cai; R. van Veldhoven; H. Suy; G. de Graaf; K. A. A. Makinwa; M. A. P. Pertijs;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 332-333, February 2018. DOI: 10.1109/ISSCC.2018.8310319

  13. CMOS-Compatible Carbon Dioxide Sensors
    Z. Cai; R. van Veldhoven; H. Suy; G. de Graaf; K. A. A. Makinwa; M. Pertijs;
    In Proc. Workshop on Advances in Analog Circuit Design (AACD),
    pp. 68-91, April 2018. invited paper. DOI: 10.1007/978-3-319-97870-3
    document

  14. A Phase-Domain Readout Circuit for a CMOS Compatible Thermal-Conductivity-Based Carbon Dioxide Sensor
    Z. Cai; R. van Veldhoven; H. Suy; G. de Graaf; K. A. A. Makinwa; M. A. P. Pertijs;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 332-333, February 2018. DOI: 10.1109/ISSCC.2018.8310319

  15. Multi-domain spectroscopy for composition measurement of water-containing bio-ethanol fuel
    L.M. Middelburg; G. de Graaf; A. Bossche; J. Bastemeijer; M. Ghaderi; F.S. Wolffenbuttel; J. Visser; R. Soltis; R.F. Wolffenbuttel;
    Fuel Processing Technology,
    Volume 167, pp. 127-135, 2017. DOI: 10.1016/j.fuproc.2017.06.007
    Abstract: ... Measuring the ethanol/water ratio in biofuel of high ethanol content, such as E85, is important when used in a flex-fuel engine. A capacitive probe is generally used for measuring the ethanol/gasoline ratio. However, the water content in E85 biofuel cannot be disregarded or considered constant and full composition measurement of biofuel is required. Electric impedance spectroscopy with a customized coaxial probe operating in the 10 kHz to 1 MHz frequency range was investigated. An in-depth investigation of the electrical impedance domain has led to the conclusion that additional information is required to unambiguously determine the composition of the ternary biofuel mixture. Among the different options of measurement domains and techniques, optical absorption spectroscopy in the UV spectral range between 230 and 300 nm was found to be the most appropriate. The typical absorbance in the UV range is highly dominated by gasoline, while ethanol and water are almost transparent. This approach is experimentally validated using actual fuels.

  16. Multi-domain spectroscopy for composition measurement of water-containing bio-ethanol fuel
    L.M. Middelburg; G. de Graaf; A. Bossche; J.Bastemeijer; M. Ghaderi; F.S. Wolffenbuttel; J. Visser; R. Soltis; R.F. Wolffenbuttel;
    Fuel Processing Technology,
    Volume 167, pp. 127-135, 2017.

  17. Combining impedance spectroscopy with optical absorption spectroscopy in the UV for biofuel composition measurement
    L. Middelburg; M. Ghaderi; A. Bossche; J. Bastemeijer; G. de Graaf; R.F. Wolffenbuttel; R. Soltis; J. Visser;
    In Instrumentation and Measurement Technology Conference (I2MTC), 2017 IEEE International,
    IEEE, IEEE, pp. 1-6, 05 2017. DOI: 10.1109/i2mtc.2017.7969676
    Abstract: ... A capacitive probe is generally used in a flex-fuel engine for measuring the ethanol content in biofuel. However, the water content in biofuel of high ethanol content cannot be disregarded or considered constant and the full composition measurement of ethanol, gasoline and water in biofuel is required. Electrical impedance spectroscopy with a customized capacitive probe operating in the 10 kHz to 1 MHz frequency range is combined with optical absorption spectroscopy in the UV spectral range between 230 and 300 nm for a full composition measurement. This approach is experimentally validated using actual fuels and the results demonstrate that electrical impedance spectroscopy when supplemented with optical impedance spectroscopy can be used to fully determine the composition of the biofuel and applied for a more effective engine management. A concept for a low-cost combined measurement system in the fuel line is presented.

  18. Heart rate monitoring using infrared thermometry in an earpiece
    D. Kuratomi Cruz; G. de Graaf; J.C. Haartsen; F. Hooijschuur; P.J. French;
    In Ravinder Dahiya, Srinivas Tadigadapa (Ed.), 2017 IEEE SENSORS,
    IEEE, IEEE, pp. 3, November 2017.
    Keywords: ... Heart rate; Infrared Thermometry; Wavelet Transform..

    Abstract: ... Heart rate is a key factor in cardiovascular system monitoring and sports science. Some recent commercial applications use sensors in the ear but are faced with motion artifacts which corrupts the signal. Infrared thermography is a non-contact technique and may minimize motion effects with better user comfort and lower power consumption. We propose a novel system that uses infrared differential thermometry to detect the heart rate in the auricle. The signal analysis is performed using a continuous wavelet transform which extract frequency features of the bioheat transfer waveforms. Preliminary results taken from the neck provide proof of concept and similar results from the ear are expected.

    ISBN: 978-1-5090-1012-7

  19. Combining impedance spectroscopy with optical absorption spectroscopy in the UV for biofuel composition measurement
    Luke Middelburg; Mohammadamir Ghaderi; Andre Bossche; Jeroen Bastemeijer; Ger de Graaf; Reinoud Wolffenbuttel;
    In Instrumentation and Measurement Technology Conference (I2MTC), 2017 IEEE International,
    2017.

  20. Micro thermal conductivity detector with flow compensation using a dual MEMS device
    G. de Graaf; A.A. Prouza; M. Ghaderi; R.F. Wolffenbuttel;
    Sensors and Actuators A: Physical,
    Volume 249, pp. 186-198, 2016.

  21. A miniaturized optical gas-composition sensor with integrated sample chamber
    Ayerden, N. Pelin; Ghaderi, Mohammadamir; Enoksson, Peter; de Graaf, Ger; Wolffenbuttel, Reinoud F.;
    Sensors and Actuators B: Chemical,
    Volume 236, pp. 917-925, 2016.

  22. Thermal annealing of thin PECVD silicon-oxide films for airgap-based optical filters
    M. Ghaderi; G. de Graaf; R.F. Wolffenbuttel;
    Journal of Micromechanics and Microengineering,
    Volume 26, Issue 8, pp. 084009, 2016.

  23. Compact gas cell integrated with a linear variable optical filter
    N.P. Ayerden; G. de Graaf; R.F. Wolffenbuttel;
    Optics Express,
    Volume 24, Issue 3, pp. 2981-3002, 2016.

  24. NBI Optical Filters in Minimally Invasive Medical Devices
    M.F. Silva; J.A. Rodrigues; M. Ghaderi; L.M. Goncalves; G. de Graaf; R.F. Wolffenbuttel; J.H. Correia;
    IEEE Journal of Selected Topics in Quantum Electronics,
    Volume 22, Issue 4, pp. 1-7, 2016.

  25. Fabrication of Ultrathin Large-area Dielectric Membrane Stacks for use as Interference Filters
    M. Ghaderi; G. de Graaf; R.F. Wolffenbuttel;
    In Procedia Engineering (Proceedings of the 30th Eurosensors Conference), vol. 168,
    Elsevier, pp. 1342-1345, 2016.

  26. Implementation of CMOS-compatible Metamaterial Absorber for gas Sensing Application
    E. Karimi Shahmarvandi; M. Ghaderi; P. Ayerden; G. de Graaf; R.F. Wolffenbuttel;
    In Procedia Engineering (Proceedings of the 30th Eurosensors Conference), vol. 168,
    Elsevier, pp. 1241-1244, 2016.

  27. Optical Spectroscopy for Biofuel Composition Sensing
    L.M. Middelburg; G. de Graaf; M. Ghaderi; A. Bossche; J.H. Bastemeijer; J.H. Visser; R.F. Wolffenbuttel;
    In Procedia Engineering (Proceedings of the 30th Eurosensors Conference), vol. 168,
    Elsevier, pp. 55-58, 2016.

  28. CMOS-compatible metamaterial-based wideband mid-infrared absorber for microspectrometer applications
    Karimi Shahmarvandi, Ehsan; Ghaderi, Mohammadamir; Ayerden, N. Pelin; de Graaf, Ger; Wolffenbuttel, Reinoud F.;
    In Proceedings of SPIE Photonics Europe, vol. 9883,
    SPIE, pp. 988309-988309-9, 2016.

  29. Analysis of the effect of stress-induced waviness in airgap-based optical filters
    M. Ghaderi; E.K. Shahmarvandi; G. de Graaf; R.F. Wolffenbuttel;
    In Proceedings of SPIE Photonics Europe, vol. 9889,
    SPIE, pp. 98890A-98890A, 2016.

  30. Design and fabrication of ripple-free CMOS-compatible stacked membranes for airgap optical filters for UV-visible spectrum
    M. Ghaderi; G. de Graaf; R.F. Wolffenbuttel;
    In Proceedings of SPIE Photonics Europe, vol. 9888,
    SPIE, pp. 98880R-98880R-8, 2016.

  31. A highly miniaturized NDIR methane sensor
    N.P. Ayerden; G. de Graaf; P. Enoksson; R.F. Wolffenbuttel;
    In Proceedings of SPIE Photonics Europe, vol. 9888,
    SPIE, pp. 98880D-98880D, 2016.

  32. Optical Spectroscopy for Biofuel Composition Sensing
    L.M. Middelburg; G. de Graaf; M. Ghaderi; A.Bossche; J. Bastemeijer; J.H. Visser; R.E. Soltis; R.F. Wolffenbuttel;
    In Procedia Engineering (Eurosensors 2016),
    pp. 55-58, 2016.

  33. Minimizing stress in large-area surface micromachined perforated membranes with slits
    M. Ghaderi; N.P. Ayerden; G. de Graaf; R.F. Wolffenbuttel;
    Journal of Micromechanics and Microengineering,
    Volume 25, Issue 7, pp. 1-9, 2015.

  34. Silicon-Based Technology for Integrated Waveguides and mm-Wave Systems
    Jovanović, Vladimir; Gentile, Gennaro; Dekker, Ronald; de Graaf, Pascal; de Vreede, Leo C. N.; Nanver, Lis K.; Spirito, Marco;
    IEEE Transactions on Electron Devices,
    Volume 62, Issue 10, pp. 3153-3159, 2015. DOI: 10.1109/TED.2015.2466441

  35. Active guarding of a four-point impedance probe with one common guard electrode for maximum readout bandwidth
    R.F. Wolffenbuttel; G. de Graaf;
    In P Daponte; S Shirmohammadi; {van Moer}, W (Ed.), IEEE International Instrumentation and Measurement Technology Conference (I2MTC) Proceedings,
    IEEE, pp. 2101-2105, 2015.

  36. Dielectric spectroscopy for measuring the composition of gasoline/water/ethanol mixtures
    G. de Graaf; G. Lacerenza; R.F. Wolffenbuttel; J. Visser;
    In P Daponte; S Shirmohammadi; {van Moer}, W (Ed.), IEEE International Instrumentation and Measurement Technology Conference (I2MTC) Proceedings,
    IEEE, pp. 154-158, 2015.

  37. A miniaturized optical sensor with integrated gas cell
    N.P. Ayerden; M. Ghaderi; G. de Graaf; R.F. Wolffenbuttel;
    In G Urban; J Wöllenstein; J Kieninger (Ed.), Procedia Engineering (Proceedings of the 29th Eurosensors Conference), vol. 120,
    Elsevier, pp. 392-395, 2015.

  38. Flow compensation in a MEMS dual-thermal conductivity detector for hydrogen sensing in natural gas
    G. de Graaf; A. Abarca Prouza; R.F. Wolffenbuttel;
    In TW Kenny; VM Bright (Ed.), Proceedings of the 18th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS),
    IEEE, pp. 1203-1206, 2015.

  39. Vapour HF release of airgap-based UV-visible optical filters
    M. Ghaderi; N.P. Ayerden; G. de Graaf; R.F. Wolffenbuttel;
    In G Urban; J Wöllenstein; J Kieninger (Ed.), Procedia Engineering (Proceedings of the 29th Eurosensors Conference), vol. 120,
    Elsevier, pp. 816-819, 2015.

  40. Optical characterization of MEMS-based multiple air-dielectric blue-spectrum distributed bragg reflectors
    M. Ghaderi; N.P. Ayerden; G. de Graaf; R.F. Wolffenbuttel;
    In R Brama; JL Sánchez-Rojas (Ed.), Proceedings of SPIE Smart Sensors, Actuators, and MEMS VII; and Cyber Physical Systems, vol. 9517,
    SPIE, pp. 95171M-1-9517, 2015.

  41. Optical design and characterization of a gas filled MEMS Fabry-Perot filter
    N.P. Ayerden; M. Ghaderi; G. de Graaf; R.F. Wolffenbuttel;
    In JL Sanchez-Rojas; R Brama (Ed.), Proceedings of SPIE Smart Sensors, Actuators, and MEMS VII; and Cyber Physical Systems, vol. 9517,
    SPIE, pp. 95171N-95171N-8, 2015.

  42. A MEMS flow compensated thermal conductivity detector for gas sensing
    G. de Graaf; A. Abarca; M. Ghaderi; R.F. Wolffenbuttel;
    In J Wollenstein (Ed.), Procedia Engineering (Proceedings of the 29th Eurosensors Conference), vol. 120,
    Elsevier, pp. 1265-1268, 2015.

  43. Optomechanical characterization of annealed thin PECVD oxide membranes
    M. Ghaderi; G. de Graaf; R.F. Wolffenbuttel;
    In RJ Wiegerink; D Tsoukalas; U. Staufer (Ed.), Proceedings of the 26th Micromechanics and Microsystems Europe workshop,
    2015.

  44. Design, fabrication and characterization of infrared LVOFs for measuring gas composition
    M. Ghaderi; N.P. Ayerden; A. Emadi; P. Enoksson; J.H. Correia; G. de Graaf; R.F. Wolffenbuttel;
    Journal of Micromechanics and Microengineering,
    Volume 24, Issue 8, pp. 1-8, 2014.

  45. Gas viscosity sensing based on the electrostatic pull-in time of microactuators
    R.A. Dias; G. de Graaf; R.F. Wolffenbuttel; L.A. Machado da Rocha;
    Sensors and Actuators A: Physical: an international journal devoted to research and development of physical and chemical transducers,
    Volume 216, pp. 376-385, 2014.

  46. Design, fabrication and characterization of LVOF-based IR microspectrometers
    N.P. Ayerden; M. Ghaderi; M.F. Silva; A. Emadi; P. Enoksson; J.H. Correia; G. de Graaf; R.F. Wolffenbuttel;
    In H Thienpont; J Mohr; H Zappe; H Nakajima (Ed.), Proceedings of SPIE Photonics Europe, vol. 9130,
    SPIE, pp. 91300T-91300T-1, 2014.

  47. A blue optical filter for narrow-band imaging in endoscopic capsules
    M.F. Silva; M. Ghaderi; Luis Miguel Goncalves; G. de Graaf; R.F. Wolffenbuttel; J.H.G. Correia;
    In J Popp; VV Tuchin; DL. Matthews; FS Pavone (Ed.), Proceedings of SPIE Photonics Europe, vol. 9129,
    SPIE, pp. 912915-912915-8, 2014.

  48. A Lossy Fabry-perot Based Optical Filter for Natural Gas Analysis
    Ayerden, NP; Ghaderi, M; De Graaf, G; Wolffenbuttel, RF;
    In Procedia Engineering (Proceedings of the 28th Eurosensors Conference), vol. 87,
    Elsevier, pp. 1410-1413, 2014.

  49. Optical filter for providing the required illumination to enable narrow band imaging
    Silva, MF; Rodrigues, JA; Oliveira, MJ; Fernandes, AR; Pereira, S; Costa, CG; Ghaderi, M; Ayerden, P; Goncalves, LM; De Graaf, G; others;
    In Procedia Engineering (Proceedings of the 28th Eurosensors Conference), vol. 87,
    Elsevier, pp. 1414-1417, 2014.

  50. Surface-micromachined bragg reflectors based on multiple airgap/sio2 layers for cmos-compatible fabry-perot filters in the uv-visible spectral range
    Ghaderi, M; Ayerden, NP; De Graaf, G; Wolffenbuttel, RF;
    In Procedia Engineering (Proceedings of the 28th Eurosensors Conference), vol. 87,
    Elsevier, pp. 1533-1536, 2014.

  51. Optical filter for providing the required illumination to enable narrow band imaging
    M.F. Silva; J.A. Rodrigues; M.J. Oliveira; A.R. Fernandes; S. Pereira; C.G. Costa; M. Ghaderi; P. Ayerden; L.M. Goncalves; G. de Graaf; R.F. Wolffenbuttel; J.H. Correia;
    In Procedia Engineering (Proceedings of the 28th Eurosensors Conference), vol. 87,
    Elsevier, pp. 1414-1417, 2014.

  52. Silicon-Filled Rectangular Waveguides and Frequency Scanning Antennas for mm-Wave Integrated Systems
    Gentile, Gennaro; Jovanović, Vladimir; Pelk, Marco J.; Jiang, Lai; Dekker, Ronald; de Graaf, P.; Rejaei, Behzad; de Vreede, Leo C. N.; Nanver, Lis K.; Spirito, Marco;
    IEEE Transactions on Antennas and Propagation,
    Volume 61, Issue 12, pp. 5893-5901, 2013. DOI: 10.1109/TAP.2013.2281518

  53. Gas viscosity MEMS sensor based on pull-in
    R.A. Dias; G. de Graaf; R.F. Wolffenbuttel; L.A. Machado da Rocha;
    In JR Morante (Ed.), Proceedings of Transducers Eurosensors XXVII: The 17th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS EUROSENSORS XXVII),
    IEEE, pp. 980-983, 2013.

  54. A review of visible-range Fabry-Perot microspectrometers in silicon for the industry
    Carmo Paulo Joao; R.P. Rocha; M. Bartek; G. de Graaf; R.F. Wolffenbuttel; J.H. Correia;
    Optics & Laser Technology,
    Volume 44, Issue 7, pp. 2312-2320, 2012.

  55. A review of visible-range Fabry�Perot microspectrometers in silicon for the industry
    J.P. Carmoa; R.P. Rocha; M. Bartek; G. de Graaf; R.F. Wolffenbuttel; J.H. Correia;
    Optics & Laser Technology,
    Volume 44, Issue 7, pp. 2312-2320, Oct. 2012. DOI 10.1016/j.optlastec.2012.03.036.

  56. Linear variable optical filter-based ultraviolet microspectrometer
    Emadi, Arvin; Wu, Huaiwen; de Graaf, Ger; Enoksson, Peter; Correia, Jose Higino; Wolffenbuttel, Reinoud;
    Applied optics,
    Volume 51, Issue 19, pp. 4308-4315, 2012.

  57. Design and implementation of a sub-nm resolution microspectrometer based on a Linear-Variable Optical Filter
    Emadi, Arvin; Wu, Huaiwen; de Graaf, Ger; Wolffenbuttel, Reinoud;
    Optics Express,
    Volume 20, Issue 1, pp. 489-507, 2012.

  58. Lock-in amplifier techniques for low-frequency modulated sensor applications
    G. de Graaf; R.F. Wolffenbuttel;
    In G Brasseur (Ed.), IEEE International Instrumentation and Measurement Technology Conference Proceedings,
    IEEE, pp. 1745-1749, 2012.

  59. Surface-micromachined thermal conductivity detectors for gas sensing
    G. de Graaf; R.F. Wolffenbuttel;
    In G Brasseur (Ed.), IEEE International Instrumentation and Measurement Technology Conference Proceedings,
    IEEE, pp. 1861-1864, 2012.

  60. Silicon integrated waveguide technology for mm-wave frequency scanning array
    Gentile, G.; Spirito, M.; de Vreede, L.C.N; Rejaei, B.; Dekker, R.; de Graaf, P.;
    In 2012 7th European Microwave Integrated Circuit Conference,
    pp. 234-237, 2012.

  61. Design, fabrication and measurements with a UV linear-variable optical filter microspectrometer
    Emadi, Arvin; Wu, Huaiwen; de Graaf, Ger; Enoksson, Peter; Correia, Jos{\'e} Higino; Wolffenbuttel, Reinoud;
    In Proceedings of SPIE Photonics Europe, vol. 8439,
    SPIE, pp. 84390V-84390V, 2012.

  62. Design and implementation of IR microspectrometers based on linear-variable optical filters
    Emadi, Arvin; Wu, Huaiwen; de Graaf, Ger; Wolffenbuttel, Reinoud;
    In Proceedings of SPIE Photonics Europe, vol. 8439,
    SPIE, pp. 84391O-84391O, 2012.

  63. Design, fabrication and measurements with a UV linear-variable optical filter microspectrometer
    Emadi, Arvin; Wu, Huaiwen; de Graaf, Ger; Enoksson, Peter; Correia, Jos{\'e} Higino; Wolffenbuttel, Reinoud;
    In Proceedings of SPIE Photonics Europe, vol. 8439,
    SPIE, pp. 84390V-84390V, 2012.

  64. A surface micromachined thermopile detector array with an interference-based absorber
    H. Wu; A. Emadi; P.M. Sarro; G. de Graaf; R.F. Wolffenbuttel;
    Journal of Micromechanics and Microengineering,
    Volume 21, Issue 7, pp. 1-8, Jun. 2011. DOI 10.1088/0960-1317/21/7/074009.

  65. A surface micromachined thermopile detector array with an interference-based absorber
    H.W. Wu; A. Emadi; P.M. Sarro; G. de Graaf; R.F. Wolffenbuttel;
    Journal of Micromechanics and Microengineering,
    Volume 21, Issue 7, pp. 1-8, 2011.

  66. Enhanced Sensitivity Computation for BEM Based Capacitance Extraction Using the Schur Complement Technique
    Yu Bi; S. de Graaf; N.P. van der Meijs;
    In IEEE Custom Integrated Circuits Conference (CICC),
    San Jose (CA), IEEE, September 2011.
    document

  67. Use of multi-wall carbon nanotubes as an absorber in a thermal detector
    H. Wu; S. Vollebregt; A. Emadi; G. de Graaf; R. R. IshiharaF. Wolffenbuttel;
    In C. Tsamis; G. Kaltas (Ed.), Proc. Eurosensors XXV,
    Athens, Greece, Procedia Engineering, pp. 523-526, Sep. 2011. DOI 10.1016/j.proeng.2011.12.130.

  68. Millimeter-wave integrated waveguides on silicon
    G. Gentile; R. Dekker; P. de Graaf; M. Spirito; L.C.N. de Vreede; B. Rejaei;
    In Proc. 2011 IEEE Topical Meeting on Silicon Monolithic Integrated Circuits RF Systems (SiRF 2011),
    Phoenix, AZ, pp. 37-40, Jan. 2011. ISBN 978-1-4244-8060-9; DOI 10.1109/SIRF.2011.5719314.

  69. Sensor platform for natural gas composition measurement
    G. de Graaf; F. Bakker; R.F. Wolffenbuttel;
    In G Kaltsas; C Tsamis (Ed.), 25th Eurosensors Conference,
    Elsevier, pp. 1157-1160, 2011.

  70. Use of multi-wall carbon nanotubes as an absorber in a thermal detector
    H. Wu; S. Vollebregt; A. Emadi; G. de Graaf; R. Ishihara; R.F. Wolffenbuttel;
    In C Tsamis; G Kaltas (Ed.), 25th Eurosensors Conference,
    Elsevier, pp. 523-526, 2011.

  71. A model for static and dynamic thermal analysis of thin film MEMS structures including the thermal conductivity of the surrounding gas
    G. de Graaf; H.W. Wu; R.F. Wolffenbuttel;
    In {De Saint Leger et al}, O (Ed.), 12th Intl. Conf. on Thermal, Mechanical Multi-Physics Simulation and Experiments in Microelectronics and Microsystems,
    IEEE, pp. 1/5-5/5, 2011.

  72. IR microspectrometers based on linear-variable optical filters
    A. Emadi; H.W. Wu; G. de Graaf; R.F. Wolffenbuttel;
    In G Kaltsas; C Tsamis (Ed.), 25th Eurosensors Conference,
    Elsevier, pp. 1401-1404, 2011.

  73. Design and fabrication of an Albedo insensitive analog sun sensor
    H.W. Wu; A. Emadi; G. de Graaf; J. Leijtens; R.F. Wolffenbuttel;
    In G Kaltsas; C Tsamis (Ed.), 25th Eurosensors Conference,
    Elsevier, pp. 527-530, 2011.

  74. Phase readout of thermal conductivity-based gas sensors
    C.P.L. van Vroonhoven; G. de Graaf; K.A.A. Makinwa;
    In {De Venuto}, D; L Benini (Ed.), 4th IEEE International Workshop on Advances in Sensors and Interfaces (IWASI),
    IEEE, pp. 199-202, 2011.

  75. Millimeter-wave integrated waveguides on silicon
    Gentile, G.; Dekker, R.; de Graaf, P.; Spirito, M.; de Vreede, L. C. N.; Rejaei, B.;
    In 2011 IEEE 11th Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems,
    pp. 37-40, 2011. DOI: 10.1109/SIRF.2011.5719314

  76. Fabrication and characterization of IC compatible linear variable optical filters with application in a micro spectrometer
    A. Emadi; H.W. Wu; S. Grabarnik; G. de Graaf; K. Hedsten; P. Enoksson; J.H.G. Correia; R.F. Wolffenbuttel;
    Sensors and Actuators A: Physical: an international journal devoted to research and development of physical and chemical transducers,
    Volume 162, Issue 2, pp. 400-405, 2010.

  77. Silicon Filled Integrated Waveguides
    Gentile, G.; Dekker, Ronald; de Graaf, Pascal; Spirito, M.; Pelk, M. J.; de Vreede, L. C. N.; Rejaei Salmassi, B.;
    IEEE Microwave and Wireless Components Letters,
    Volume 20, Issue 10, pp. 536-538, 2010. DOI: 10.1109/LMWC.2010.2063420

  78. Surface micromached gas sensor using thermopiles for carbon dioxide detection
    S. Chen; H.W. Wu; G. de Graaf; R.F. Wolffenbuttel;
    {van Honschoten}, J; H Verputten; H Groenland (Ed.);
    MME, , pp. 216-219, 2010.

  79. Spectral measurement using IC compatible linear variable optical filter
    A. Emadi; H. Wu; S. Grabarnik; G. de Graaf; K. Hedsten; P. Enoksson; J.H.G. Correia; R.F. Wolffenbuttel;
    H Thienpont; {van Daele}, P; J Mohr; H Zappe (Ed.);
    SPIE, , pp. 1-6, 2010.

  80. Thermal analysis, fabrication and signal processing of surface microma-chined thermal conductivity based gas sensors
    G. de Graaf; H. Wu; R.F. Wolffenbuttel;
    L Abelmann; H Groenland; {van Honschoten}, J; H Verputten (Ed.);
    MME, , pp. 173-176, 2010.

  81. An UV linear variable optical filter based micro spectrometer
    A. Emadi; H. Wu; S. Grabarnik; G. de Graaf; K. Hedsten; P. Enoksson; J.H.G. Correia; R.F. Wolffenbuttel;
    M.J. Vellekoop (Ed.);
    Eurosensor 24, , pp. 416-419, 2010.

  82. A CMOS 128 APS linear array integrated with a LVOF for high sensitivity and high resolution micro spectrophotometry
    C. Liu; A. Emadi; H.W. Wu; G. de Graaf; R.F. Wolffenbuttel;
    F Berghmans; AG Mignani; C. van HoofA (Ed.);
    SPIE, , pp. 1-10, 2010.

  83. Encapsulated thermopile detector array for IR microspectrometer
    H. Wu; A. Emadi; G. de Graaf; R.F. Wolffenbuttel;
    MA Druy; CD Brown; RA Crocombe (Ed.);
    SPIE, , pp. 1-9, 2010.

  84. CMOS compatible LVOF based visible microspectrometer
    A. Emadi; H. Wu; S. Grabarnik; G. de Graaf; R.F. Wolffenbuttel;
    MA Druy; CD Brown; RA Crocombe (Ed.);
    SPIE, , pp. 1-8, 2010.

  85. Spectral measurement with a linear variable filter using a LMS algorithm
    A. Emadi; S. Grabarnik; H. Wu; G. de Graaf; R.F. Wolffenbuttel;
    MJ vellekoop (Ed.);
    Eurosensor 24, , pp. 504-507, 2010.

  86. Post processing of linear variable optical filter on CMOS chip at die-level
    A. Emadi; H. Wu; G. de Graaf; R.F. Wolffenbuttel;
    {van Honschoten}, J; H Verputten; H Groenland (Ed.);
    MME, , pp. 185-188, 2010.

  87. Silicon carbide thin film encapsulation of planar thermo- electric infrared detectors for an IR microspectrometer
    V. Rajaraman; G. de Graaf; P.J. French; K.A.A. Makinwa; R.F. Wolffenbuttel;
    {van Honschoten}, J; H Verputten; H Groenland (Ed.);
    MME, , pp. 20-23, 2010.

  88. Thin film encapsulated 1D thermoelectric detector in an IR microspectrometer
    H. Wu; A. Emadi; G. de Graaf; R.F. Wolffenbuttel;
    F Berghmans; AG Mignani; C. van HoofA (Ed.);
    SPIE, , pp. 1-8, 2010.

  89. Interference filter based absorber for thermopile detector array by surface micromachining
    H. Wu; A. Emadi; G. de Graaf; R.F. Wolffenbuttel;
    L Abelmann; H Groenland; {van Honschoten}, J; H Verputten (Ed.);
    MME, , pp. 169-172, 2010.

  90. Linear variable optical filter with silver metallic layers
    A. Emadi; S. Mokkapati; H. Wu; G. de Graaf; R.F. Wolffenbuttel;
    {van Honschoten}, J; H Verputten; H Groenland (Ed.);
    MME, , pp. 104-107, 2010.

  91. High-aspect-ratio through-wafer parylene beams for stretchable silicon electronics.
    T. Zoumpoulidis; M. Bartek; P. de Graaf; R. Dekker;
    Sensors and actuators a-physical,
    Volume 156, Issue 1, pp. 257-264, 2009. ISSN 0924-4247.

  92. Characterization of thermal cross-talk in a MEMS-based thermopile detector array
    H.W. Wu; S. Grabarnik; A. Emadi; G. de Graaf; R.F. Wolffenbuttel;
    Journal of Micromechanics and Microengineering,
    Volume 19, pp. 74022(1)-74022, 2009.

  93. Vertically tapered layers for optical applications fabricated using resist reflow
    A. Emadi; H.W. Wu; S. Grabarnik; G. de Graaf; R.F. Wolffenbuttel;
    Journal of Micromechanics and Microengineering,
    Volume 19, pp. 074014(1)-0740, 2009.

  94. Self-powered sun sensor microsystems
    H.W. Wu; A. Emadi; G. de Graaf; J. Leijtens; R.F. Wolffenbuttel;
    s.n. (Ed.);
    Eurosensors, , pp. 1-4, 2009.

  95. Microspectrometer with a concave grating fabricated in a MEMS technology
    S. Grabarnik; A. Emadi; H.W. Wu; G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    Eurosensors, , pp. 1-4, 2009.

  96. IC-compatible fabrication of linear variable optical filters for micro-spectrometer
    A. Emadi; H.W. Wu; S. Grabarnik; G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    Eurosensors, , pp. 1-4, 2009.

  97. Study of thermal cross-talk in micromachined thermopile based infrared detector arrays
    H.W. Wu; S. Grabarnik; A. Emadi; G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    STW, , pp. 1-4, 2009.

  98. Self-powered optical sensor systems
    H.W. Wu; A. Emadi; G. de Graaf; J. Leijtens; R.F. Wolffenbuttel;
    s.n. (Ed.);
    Transducers, , pp. 1373-1376, 2009.

  99. Interference filter based IR absorber for MEMS thermopile array
    A. Emadi; H.W. Wu; S. Grabarnik; G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    MME, , pp. 1-4, 2009.

  100. Thermal cross-talk in IC-compatible micromachined infrared thermopile detector arrays
    H.W. Wu; S. Grabarnik; G. de Graaf; A. Emadi; R.F. Wolffenbuttel;
    s.n. (Ed.);
    IRS, , pp. 319-323, 2009.

  101. Fabrication and characterization of IC-compatible multilayer interference filters
    G. de Graaf; A. Emadi; R.F. Wolffenbuttel;
    s.n. (Ed.);
    IRS, , pp. 313-317, 2009.

  102. A Precise SystemC-AMS Model For Charge Pump Phase Lock Loop With Multiphase Output
    Tao Xu; R. van Leuken; H. Lincklaen Arriens; A. de Graaf;
    In IEEE 8th Int. Conf. on ASIC (Asicon),
    Changsha (China), IEEE, October 2009.
    document

  103. A Precise System-C-AMS model for charge pump phase lock loop verified by its CMOS circuit
    Tao Xu; H. Lincklaen Arriens; R. van Leuken; A. de Graaf;
    In 20th annual workshop on circuits, systems and signal processing--ProRISC,
    Veldhoven, STW, pp. 412-417, November 2009. ISBN 978-90-73461-62-8.
    document

  104. Fabrication of an imaging diffraction grating for use in a MEMS-based optical microspectrograph
    S. Grabarnik; A. Emadi; H.W. Wu; G. de Graaf; G.V. Vdovin; R.F. Wolffenbuttel;
    Journal of Micromechanics and Microengineering,
    Volume 18, Issue 6, 2008.

  105. High-resolution microspectrometer with an aberration-correcting planar grating
    S. Grabarnik; A. Emadi; H.W. Wu; G. de Graaf; R.F. Wolffenbuttel;
    Applied Optics,
    Volume 47, pp. 6442-6447, 2008.

  106. A thermopile detector array with scaled TE elements for use in an integrated IR microspectrometer
    H.W. Wu; S. Grabarnik; A. Emadi; G. de Graaf; R.F. Wolffenbuttel;
    Journal of Micromechanics and Microengineering,
    Volume 18, Issue 6, 2008.

  107. Planar MEMS-compatible microspectrograph
    S. Grabarnik; A. Emadi; H.W. Wu; G. de Graaf; G.V. Vdovin; R.F. Wolffenbuttel;
    s.n. (Ed.);
    apcot, , pp. 53-56, 2008.

  108. Design and fabrication of a thermopile detector array with scaled elements for an integrated IR microspectrometer
    H.W. Wu; A. Emadi; W. van der Vlist; S. Grabarnik; G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    apcot, , pp. 213-216, 2008.

  109. Optical microspectrometer with planar grating and external spherical
    S. Grabarnik; A. Emadi; H.W. Wu; G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    Eurosensors, , pp. 350-353, 2008.

  110. Fabrication of trapped optical structures using resist reflow
    A. Emadi; H.W. Wu; S. Grabarnik; G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    MME, , pp. 113-116, 2008.

  111. IC-compatible microspectrometer using a planar imaging diffraction grating
    S. Grabarnik; A. Emadi; H.W. Wu; G. de Graaf; G.V. Vdovin; R.F. Wolffenbuttel;
    s.n. (Ed.);
    SPIE, , pp. 1-10, 2008.

  112. Characterization of thermal cross-talk in a thermopile detector
    H.W. Wu; S. Grabarnik; G. de Graaf; A. Emadi; R.F. Wolffenbuttel;
    s.n. (Ed.);
    MME, , pp. 415-418, 2008.

  113. Simulation and analytical calculation of reflowed resist structures
    A. Emadi; H.W. Wu; S. Grabarnik; G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    MME, , pp. 347-350, 2008.

  114. Cross-talk characterization of thermal detector array
    H.W. Wu; S. Grabarnik; A. Emadi; G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    Eurosensors, , pp. 366-369, 2008.

  115. Concave diffraction gratings fabricated with planar lithography
    S. Grabarnik; A. Emadi; H.W. Wu; G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    SPIE, , pp. 1-8, 2008.

  116. Mid infrared microspectrometer systems
    G. de Graaf;
    PhD thesis, Delft University of Technology, 2008.

  117. Infrared thermopile detector array for the integrated micro spectrometer
    A. Emadi; H.W. Wu; S. Grabarnik; G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    IEEE, , pp. 435-438, 2007.

  118. Design and fabrication of an infrared microspectrometer using attenuated total reflection
    G. de Graaf; W. van der Vlist; R.F. Wolffenbuttel;
    s.n. (Ed.);
    IEEE, , pp. 1395-1399, 2007.

  119. Spectral sensor basedon an imaging diffraction grating and fabricated with MEMS technologies
    S. Grabarnik; A. Emadi; H.W. Wu; G. de Graaf; G.V. Vdovin; R.F. Wolffenbuttel;
    s.n. (Ed.);
    MME, , pp. 175-178, 2007.

  120. Design and fabrication of thermopile detector array for microspectrometer application
    H.W. Wu; A. Emadi; G. de Graaf; S. Grabarnik; R.F. Wolffenbuttel;
    s.n. (Ed.);
    MME, , pp. 103-106, 2007.

  121. Fabrication and characterization of infra-red multi-layered interference filter
    A. Emadi; S. Grabarnik; H.W. Wu; G. de Graaf; R.F. Wolffenbuttel;
    MME, , pp. 249-252, 2007.

  122. An MCM based microsystem for calorimetric detection of niomolecules in biological fluids (U-SP-2-I-ICT)
    G. de Graaf; R.F. Wolffenbuttel; G. Minas; J.H.G. Correia;
    IEEE Sensors Journal,
    Volume 6, Issue 4, pp. 1003-1009, 2006.

  123. Systematic approach for the linearization and readout of non-symmetric impedance bridges (U-SP-2-I-ICT)
    R.F. Wolffenbuttel; G. de Graaf;
    IEEE Transactions on Instrumentation and Measurement,
    Volume 55, Issue 5, pp. 1566-1572, 2006.

  124. Silicon compatible Fabry-perot optical filters for mid-IR microspectrometer applications (U-SP-2-I-ICT)
    A. Emadi; G. de Graaf; R.F. Wolffenbuttel; J.H.G. Correia;
    s.n. (Ed.);
    Eurosensors, , pp. 1-4, 2006.

  125. Fabrication of an in Infrared microspectrometer using evanescent wave sensing (U-SP-2-I-ICT)
    G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    Eurosensors, , pp. 1-4, 2006.

  126. Pre-distorted sinewave-driven parallel-plate electrostatic actuator for harmonic displacement
    G. de Graaf; L. Mol; L.A. Rocha; E. Cretu; R.F. Wolffenbuttel;
    Journal of Micromechanics and Microengineering,
    Volume 15, pp. 103-108, 2005.

  127. Design of an infrared microspectrometer using total internal reflection
    G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    s.n., , pp. 1-4, 2005. Editor onbekend JH.

  128. High-resolution capacitive measurement of microstructure displacement using coherent detection
    L. Mol; G. de Graaf; L.A. Rocha; R.F. Wolffenbuttel;
    {R Reus}, de; {S Bouwstra} (Ed.);
    IEEE, , pp. 1-4, 2005. Editor onbekend.

  129. Optical measurements on drain fluid for the detection of anastomotic leakage
    L. Pakula; D. Tanase; G. de Graaf; P.J. French; K. Kraal; J.F. Lange;
    In s.n. (Ed.), Proceedings of the 3rd annual International IEEE EMBS Special Topic Conference on Microtechnologies in Medicine and Biology,
    IEEE, pp. 72-75, 2005. Editor onbekend JH.

  130. Illumination source identification using a CMOS optical microsystem
    G. de Graaf; R.F. Wolffenbuttel;
    IEEE Transactions on Instrumentation and Measurement,
    Volume 53, Issue 2, pp. 238-242, 2004. ed.is niet bekend.

  131. Single-chip micro-thermostat applying both active heating and active cooling
    D.D.L. Wijngaards; G. de Graaf; R.F. Wolffenbuttel;
    Sensors and Actuators A: Physical: an international journal devoted to research and development of physical and chemical transducers,
    Volume 110, pp. 187-195, 2004. ed. is niet bekend.

  132. Optical CMOS sensor system for detection of light sources
    G. de Graaf; R.F. Wolffenbuttel;
    Sensors and Actuators A: Physical: an international journal devoted to research and development of physical and chemical transducers,
    Volume 110, pp. 77-81, 2004. ed. is niet bekend.

  133. A MCM-based microsystem for biological fluids analysis by optical absorption
    G. Minas; J.C. Ribeiro; G. de Graaf; R.F. Wolffenbuttel; J.H. Correia;
    s.n. (Ed.);
    IEEE, , pp. 223-226, 2004. niet eerder opgevoerd -sb.

  134. Quadrature oscillator with pre-distorted waveforms for application in MEMS-based mechanical spectrum analyser
    G. de Graaf; L. Mol; L.A. Rocha; E. Cretu; R.F. Wolffenbuttel;
    M Steveart; CL Claeys (Ed.);
    IEEE, , pp. 407-410, 2004.

  135. Harmonic displacement of a parallel-plate electrostatic actuator using a pre-distorted sine wave oscillator
    G. de Graaf; L. Mol; L.A. Rocha; E. Cretu; R.F. Wolffenbuttel;
    s.n., , pp. 53-56, 2004. ed. is niet bekend.

  136. A systematic approach for sensor bridge linearisation and readout
    G. de Graaf; R.F. Wolffenbuttel;
    S Demidenko; R Ottoboni; D Petri; V Piuri; {Chong Tad Weng}, D (Ed.);
    IEEE, , pp. 1551-1555, 2004.

  137. Circuit for readout and linearisation of sensor bridges
    G. de Graaf; R.F. Wolffenbuttel;
    M Steveart; CL Claeys (Ed.);
    IEEE, , pp. 151-154, 2004.

  138. A high-level design and implementation platform for IP prototyping on FPGA platforms
    R. van Leuken; A.C. de Graaf; H. Lincklaen-Arriens;
    In Prorisc'04,
    Veldhoven, November 2004.

  139. A High-level Design and Implementation Platform for IP Prototyping on FPGA
    T.G.R. van Leuken; A.C. de Graaf; H.J. Lincklaen Arriens;
    In ProRISC IEEE 15th Annual Workshop on Circuits, Systems and Signal Processing,
    Veldhoven, the Netherlands, pp. 68-71, November 2004.
    document

  140. A CMOS Semi-Custom Chip for Mixed Signal Designs
    A. J. van Genderen; S. D. Cotofana; G. de Graaf; A. Kaichouhi; J. Liedorp; R. Nouta; M. A. P. Pertijs; C. J. M. Verhoeven;
    In Annual Workshop on Circuits, Systems and Signal Processing (ProRISC),
    The Netherlands, pp. 491‒496, November 2004.

  141. A CMOS Semi-Custom Chip for Mixed Signal Designs
    Van Genderen, AJ; Cotofana, SD; De Graaf, G; Kaichouhi, A; Liedorp, J; Nouta, R; Pertijs, MAP; Verhoeven, CJM;
    In Book of abstracts, ProRISC 2004,
    ProRISC, 2004.
    document

  142. Integrated silicon infrared microspectrometers
    S.H. Kong; G. de Graaf; R.F. Wolffenbuttel;
    T Gregorkiewicz; RG Elliman; PM Fauchet; JA Hutchby (Ed.);
    Materials Research Society, , pp. 1-10, 2003. CD-ROM.

  143. Performance of integrated silicon infrared microspectrometers
    S.H. Kong; G. de Graaf; L.A. Machado da Rocha; R.F. Wolffenbuttel;
    s.n. (Ed.);
    IEEE, , pp. 707-710, 2003.

  144. New concept for the linearisation of sensor bridge circuits
    G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    University of Minho, , pp. 835-838, 2003.

  145. Linearisation of Piezoresistive pressure sensor readout
    G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    s.n., , pp. 207-210, 2003.

  146. Mechanical spectrum analyzer in silicon using micromachined accelerometers with time-varying electrostatic feedback
    L.A. Machado da Rocha; E. Cretu; G. de Graaf; R.F. Wolffenbuttel;
    s.n. (Ed.);
    IEEE, , pp. 1197-1201, 2003.

  147. A Single-Chip CMOS Optical Microspectrometer with Light-to-Frequency Converter and Bus Interface
    J.H. Correia; G. de Graaf; M. Bartek; R.F. Wolffenbuttel;
    IEEE Journal of Solid-State Circuits,
    Volume 37, Issue 10, pp. 1344-1347, Oct. 2002. ISSN 0018-9200.

  148. A single-chip CMOS optical microspectrometer with light-to-frequency converter and bus interface
    J.H. Correia; G. de Graaf; M. Bartek; R.F. Wolffenbuttel;
    IEEE Journal of Solid State Circuits,
    Volume 37, Issue 10, pp. 1344-1347, 2002.

  149. A CMOS optical microspectrometer with light-to-frequency converter, bus interface, and stray-light compensation
    J.H. Correia; G. de Graaf; M. Bartek; R.F. Wolffenbuttel;
    IEEE Transactions on Instrumentation and Measurement,
    Volume 50, Issue 6, pp. 1530-1537, 2002.

  150. European Low Power Initiative for Electronic System Design; Designing CMOS for low power
    R. van Leuken; R. Nouta; A. de Graaf (Ed.);
    Kluwer academic publishers, , 2002. ISBN 1-4020-7234-1.

  151. Design of a single-chip micro-thermostat employing both active heating and active cooling
    D.D.L. Wijngaards; G. de Graaf; R.F. Wolffenbuttel;
    Nat. Inst. of Res. and Development in Microtechnologies, , pp. 189-192, 2002.

  152. Integrated CMOS optical microsystem for illuminating source identification
    G. de Graaf; R.F. Wolffenbuttel;
    IEEE Instrumentation and Measurement Society, , pp. 1-4, 2002.

  153. CMOS sensor system for measuring environmental light conditions
    G. de Graaf; R.F. Wolffenbuttel;
    Czech Technical University, , pp. 415-418, 2002.

  154. General Purpose Prototyping Platform for Data Processor Research and Development
    F. Miletic; R. van Leuken; A. de Graaf;
    In Proc. Field Programmable Logic and Applications (FPL 2002),
    Montpellier (France), September 2002.

  155. A Design Platform for Fast Prototyping of Data-processors
    F. Miletic; R. van Leuken; A. de Graaf;
    In Proceedings 17th Conference on Design of Circuits and Integrated Systems (DCIS 2002),
    Santander (Spain), pp. 119-125, November 2002.

  156. A CMOS optical microspectrometer with light-to-frequency converter, bus interface, and stray-light compensation
    J.H. Correia; G. de Graaf; M. Bartek; R.F. Wolffenbuttel;
    IEEE Trans. on Instrumentation and Measurement,
    Volume 50, Issue 6, pp. 1530-1537, Dec. 2001.

  157. Bulk micromachined electrostatic RMS-to-DC converter
    G. de Graaf; M. Bartek; Z. Xiao; C.J. van Mullem; R.F. Wolffenbuttel;
    IEEE Trans. on Instrumentation and Measurement,
    Volume 50, Issue 6, pp. 1508-1512, Dec. 2001.

  158. Integrated silicon microspectrometers
    S.-H. Kong; J.H. Correia; G. de Graaf; M. Bartek; R.F. Wolffenbuttel;
    IEEE Instrumentation & Measurement Magazine,
    Volume 4, Issue 3, pp. 34-38, Sept. 2001.

  159. Bulk micromachined electrostatic RMS-to-DC converter
    G. de Graaf; M. Bartek; Z. Xiao; C.J. Mullem; R.F. Wolffenbuttel;
    IEEE Transactions on Instrumentation and Measurement,
    Volume 50, Issue 6, pp. 1508-1512, 2001.

  160. Integrated silicon: microspectrometers
    S.H. Kong; A. Correia; G. de Graaf; M. Bartek; R.F. Wolffenbuttel;
    IEEE Instrumentation and Measurement Magazine,
    Volume 4, Issue 3, pp. 34-38, 2001.

  161. European Low Power Initiative for Electronic System Design; low power design Techniques and CAD tools for analog and RF integrated circuits
    R. van Leuken; R. Nouta; A. de Graaf (Ed.);
    Kluwer, , 2001. 294 pages. ISBN 0-7923-7432-0.

  162. European Low Power Initiative for Electronic System Design; Principles of Asynchronous Circuit Design, A systems perspective
    R. van Leuken; R. Nouta; A. de Graaf (Ed.);
    Kluwer, , 2001. 360 pages. ISBN 0-7923-7613-7.

  163. Fabrication and optical measurements of multi-slit grating based infrared micro-spectrometer
    S.H. Kong; D.D.L. Wijngaards; G. de Graaf; R.F. Wolffenbuttel;
    {E Obermeier} (Ed.);
    Springer, , pp. 548-551, 2001.

  164. Evaluation of an oscilloscope training course
    G. de Graaf; D.D.L. Wijngaards; R.F. Wolffenbuttel;
    University of Twente, , pp. 67-74, 2001.

  165. Temperature profile comparison of various substrate geometries for passive heat sinks
    D.D.L. Wijngaards; G. de Graaf; S.H. Kong; R.F. Wolffenbuttel;
    s.n., , pp. 143-146, 2001.

  166. Study of the behaviour of various substrate geometries for use as passive heat sink
    D.D.L. Wijngaards; G. de Graaf; S.H. Kong; R.F. Wolffenbuttel;
    {M Elwenspoek} (Ed.);
    Kluwer, , pp. 47-52, 2001.

  167. 4th International Workshop of the European Low Power Initiative for Electronic System Design
    R. van Leuken; R. Nouta; A. de Graaf (Ed.);
    Yverdon (Switzerland): , September 2001. 157 pages. ISBN 90-5326-038-2.

  168. Single-chip CMOS optical microspectrometer
    J.H. Correia; G. de Graaf; S.H. Kong; M. Bartek; R.F. Wolffenbuttel;
    Sensors and Actuators A,
    Volume 82, Issue 1-3, pp. 191-197, 2000. ISSN 0924-4247.

  169. Single-chip CMOS optical microspectrometer
    J.H.G. Correia; G. de Graaf; S.H. Kong; M. Bartek; R.F. Wolffenbuttel;
    Sensors and Actuators A: Physical: an international journal devoted to research and development of physical and chemical transducers,
    Volume 82, Issue 1-3, pp. 191-197, 2000.

  170. Motivation, context and objectives
    F. Catthoor; R. van Leuken; R. Nouta; A. de Graaf;
    In Unified low-power design flow for data-dominated multi-media and telecom appliocations,
    Dordrecht, Kluwer, 2000. 180 pages. ISBN 0-7923-7947-0.

  171. Low power design in Europe: a novel knowledge sharing action
    R. van Leuken; R. Nouta; A. de Graaf; M. Kouwenhoven; C. Verhoeven;
    In Design, Automation and Test in Europe Conference 2000--user forum,
    Paris (F), March 2000.

  172. Constraints, Hurdles and Opportunities for a Successful European Take-Up Action
    R. van Leuken; R. Nouta; A. de Graaf;
    In Proc. 10th International Workshop, PATMOS 2000,
    Gottingen (G), pp. 1-2, September 2000.

  173. 3rd International Workshop of the European Low power Initiative for Electronic System Design
    R. van Leuken; R. Nouta; A. de Graaf (Ed.);
    Rapallo (I): , July 2000. 298 pages. ISBN 90-5326-036-6.

  174. On-chip integrated CMOS optical microspectrometer with light-to-frequency converter and bus interface
    G. de Graaf; J.H.G. Correia; M. Bartek; R.F. Wolffenbuttel;
    {JH. Wuorinen} (Ed.);
    IEEE, , pp. 208-209, 1999.

  175. Optical microspectrometer using a micro-instrumentation platform
    M. Bartek; J.H.G. Correia; G. de Graaf; R.F. Wolffenbuttel;
    s.n., , pp. 99-106, 1999.

  176. Single-chip CMOS optical microspectrometer
    J.H.G. Correia; G. de Graaf; S.H. Kong; M. Bartek; R.F. Wolffenbuttel;
    Institute of Electrical Engineers of Japan, , pp. 869-899, 1999.

  177. 1st Int. workshop of the European Low power Initiative for Electronic System Design
    R. van Leuken; R. Nouta; A. de Graaf (Ed.);
    Como (I): , March 1999. ISBN 90 5326 035 8. 76 pages..

  178. 2nd Int. workshop of the European Low power Initiative for Electronic System Design
    R. van Leuken; R. Nouta; A. de Graaf (Ed.);
    Kos (Gr): , October 1999. ISBN 90 5326 034 X. 160 pages..

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Last updated: 8 Feb 2023

Ger de Graaf

MSc students