Academic staff

Niels Tas

3D Nano-Machining and Devices

Niels Tas is active in the field of MEMS since 1992. Initially under the supervision of Dr. Theo Lammerink, and all these years in close collaboration with Ing. Erwin Berenschot. From the mid-nineties onward the discussions with Prof. Henri Jansen (now with DTU Danchip) have led to many new research ideas. We gratefully remember the close collaboration with Dr. Joost van Honschoten, who passed away in 2011. With his talents on analytical modelling he passionately contributed to the studies on capillarity and elasto-capillarity.   

Niels Tas obtained his engineering degree (ir.) in electrical engineering  in 1995. His Thesis addressed the design and realization  of a micro-hydraulic relaxation oscillator. He obtained his PhD degree in 2000 based on his work on linear electrostatic micromotors. Since then he has worked on a broad range of topics in the MEMS/NEMS/LoC fields. He is an associate professor since 2010. Niels Tas and Erwin Berenschot are part of the MCS group headed by Prof. Han Gardeniers since 2014.

The current focus of the Tas-team is on fabrication of 3D nanostructures with employment in (electro)mechanical, fluidic, optical, electronic and magnetic domains. Typical application fields are: Energy harvesting, biomedical (drug delivery, patch clamping), chemical analysis and multi-parameter sensing, computation, and data storage.

Since 1993, Tas and co-workers delivered key-contributions  in a broad range of MEMS and NEMS topics: silicon based micro-nanomachining, micro-nanofluidics, adhesion and friction, elastic mechanics and electrostatic microactuators, elasto-capillarity, fluidic SPM, acoustic resonators, and flow sensors. Selected publications are listed below.

In his teaching, Niels Tas focusses on design of micro- and nanodevices. He is the coordinating lecturer for “MEMS Design” (191211300) and for the “Nanotechnology Design Project” (201600044).

Niels Tas is co-founder and advisor for U-Needle, a spin-off company developing and producing silicon microneedles for intradermal use.

Selected Publications

Silicon based Micro- and Nanomachining

Westerik, P.J., Vijselaar, W.J.C., Berenschot, J.W., Tas, N.R., Huskens, J., Gardeniers, J.G.E.
Sidewall patterning - A new wafer-scale method for accurate patterning of vertical silicon structures
(2018) Journal of Micromechanics and Microengineering, 28 (1), art. no. 015008
DOI: 10.1088/1361-6439/aa9c20

Wilbers, J.G.E., Berenschot, J.W., Tiggelaar, R.M., Dogan, T., Sugimura, K., Van Der Wiel, W.G., Gardeniers, J.G.E., Tas, N.R.
3D-fabrication of tunable and high-density arrays of crystalline silicon nanostructures
(2018) Journal of Micromechanics and Microengineering, 28 (4), art. no. 044003
DOI: 10.1088/1361-6439/aaab2d

Berenschot, J.W., Sun, X., Le The, H., Tiggelaar, R.M., De Boer, M.J., Eijkel, J.C.T., Gardeniers, J.G.E., Tas, N.R., Sarajlic, E.
Wafer-scale nanostructure formation inside vertical nano-pores
(2017) 2017 IEEE 12th International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2017, art. no. 8016973, pp. 57-60
DOI: 10.1109/NEMS.2017.8016973

Berenschot, E.J.W., Jansen, H.V., Tas, N.R.
Fabrication of 3D fractal structures using nanoscale anisotropic etching of single crystalline silicon
(2013) Journal of Micromechanics and Microengineering, 23 (5), art. no. 055024
DOI: 10.1088/0960-1317/23/5/055024

Burouni, N., Berenschot, E., Elwenspoek, M., Sarajlic, E., Leussink, P., Jansen, H., Tas, N.
Wafer-scale fabrication of nanoapertures using corner lithography
(2013) Nanotechnology, 24 (28), art. no. 285303
DOI: 10.1088/0957-4484/24/28/285303

Berenschot, E.J.W., Burouni, N., Schurink, B., Van Honschoten, J.W., Sanders, R.G.P., Truckenmuller, R., Jansen, H.V., Elwenspoek, M.C., Van Apeldoorn, A.A., Tas, N.R.
3D nanofabrication of fluidic components by corner lithography
(2012) Small, 8 (24), pp. 3823-3831
DOI: 10.1002/smll.201201446

Zhao, Y., Berenschot, E., Jansen, H., Tas, N., Huskens, J., Elwenspoek, M.
Multi-silicon ridge nanofabrication by repeated edge lithography
(2009) Nanotechnology, 20 (31), art. no. 315305
DOI: 10.1088/0957-4484/20/31/315305

Zhao, Y., Berenschot, E., Jansen, H., Tas, N., Huskens, J., Elwenspoek, M.
Sub-10 nm silicon ridge nanofabrication by advanced edge lithography for NIL applications
(2009) Microelectronic Engineering, 86 (4-6), pp. 832-835
DOI: 10.1016/j.mee.2008.11.067

Hoang, H.T., Segers-Nolten, I.M., Berenschot, J.W., De Boer, M.J., Tas, N.R., Haneveld, J., Elwenspoek, M.C.
Fabrication and interfacing of nanochannel devices for single-molecule studies
(2009) Journal of Micromechanics and Microengineering, 19 (6), art. no. 065017
DOI: 10.1088/0960-1317/19/6/065017

Berenschot, J.W., Tas, N.R., Jansen, H.V., Elwenspoek, M.
Chemically anisotropic single-crystalline silicon nanotetrahedra
(2009) Nanotechnology, 20 (47), art. no. 475302
DOI: 10.1088/0957-4484/20/47/475302

Berenschot, E., Tas, N.R., Jansen, H.V., Elwenspoek, M.
3D-Nanomachining using corner lithography
(2008) 3rd IEEE International Conference on Nano/Micro Engineered and Molecular Systems, NEMS, art. no. 4484432, pp. 729-732
DOI: 10.1109/NEMS.2008.4484432

Haneveld, J., Jansen, H., Berenschot, E., Tas, N., Elwenspoek, M.
Wet anisotropic etching for fluidic 1D nanochannels
(2003) Journal of Micromechanics and Microengineering, 13 (4), pp. S62-S66
DOI: 10.1088/0960-1317/13/4/310

Berenschot, J.W., Tas, N.R., Lammerink, T.S.J., Elwenspoek, M., Van Den Berg, A.
Advanced sacrificial poly-Si technology for fluidic systems
(2002) Journal of Micromechanics and Microengineering, 12 (5), pp. 621-624
DOI: 10.1088/0960-1317/12/5/317

Tas, N.R., Berenschot, J.W., Mela, P., Jansen, H.V., Elwenspoek, M., Van Den Berg, A.
2D-Confined Nanochannels Fabricated by Conventional Micromachining
(2002) Nano Letters, 2 (9), pp. 1031-1032
DOI: 10.1021/nl025693r

Jansen, H., De Boer, M., Wiegerink, R., Tas, N., Smulders, E., Neagu, C., Elwenspoek, M.
RIE lag in high aspect ratio trench etching of silicon
(1997) Microelectronic Engineering, 35 (1-4), pp. 45-50
DOI: 10.1016/S0167-9317(96)00142-6 

Micro- and Nanofluidics

de Rutte, J.M., Janssen, K.G.H., Tas, N.R., Eijkel, J.C.T., Pennathur, S.
Numerical investigation of micro- and nanochannel deformation due to discontinuous electroosmotic flow
(2016) Microfluidics and Nanofluidics, 20 (11), art. no. 150
DOI: 10.1007/s10404-016-1815-1

Das, S., Chanda, S., Eijkel, J.C.T., Tas, N.R., Chakraborty, S., Mitra, S.K.
Filling of charged cylindrical capillaries
(2014) Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 90 (4), art. no. 043011
DOI: 10.1103/PhysRevE.90.043011

Hoang, H.T., Segers-Nolten, I.M., Tas, N.R., Van Honschoten, J.W., Subramaniam, V., Elwenspoek, M.C.
Analysis of single quantum-dot mobility inside 1D nanochannel devices
(2011) Nanotechnology, 22 (27), art. no. 275201
DOI: 10.1088/0957-4484/22/27/275201

Van Honschoten, J.W., Brunets, N., Tas, N.R.
Capillarity at the nanoscale
(2010) Chemical Society Reviews, 39 (3), pp. 1096-1114
DOI: 10.1039/b909101g

van Honschoten, J.W., Escalante, M., Tas, N.R., Elwenspoek, M.
Formation of liquid menisci in flexible nanochannels
(2009) Journal of Colloid and Interface Science, 329 (1), pp. 133-139
DOI: 10.1016/j.jcis.2008.09.082

Unnikrishnan, S., Jansen, H.V., Falke, F.H., Tas, N.R., Van Wolferen, H.A.G.M., De Boer, M.J., Sanders, R.G.P., Elwenspoek, M.C.
Transition flow through an ultra-thin nanosieve
(2009) Nanotechnology, 20 (30), art. no. 305304
DOI: 10.1088/0957-4484/20/30/305304

Janssen, K.G.H., Hoang, H.T., Floris, J., De Vries, J., Tas, N.R., Eijkel, J.C.T., Hankemeier, T.
Solution titration by wall deprotonation during capillary filling of silicon oxide nanochannels
(2008) Analytical Chemistry, 80 (21), pp. 8095-8101
DOI: 10.1021/ac800603m

Haneveld, J., Tas, N.R., Brunets, N., Jansen, H.V., Elwenspoek, M.
Capillary filling of sub- 10 nm nanochannels
(2008) Journal of Applied Physics, 104 (1), art. no. 014309
DOI: 10.1063/1.2952053

Van Honschoten, J.W., Escalante, M., Tas, N.R., Jansen, H.V., Elwenspoek, M.
Elastocapillary filling of deformable nanochannels
(2007) Journal of Applied Physics, 101 (9), art. no. 094310
DOI: 10.1063/1.2732539

Brivio, M., Tas, N.R., Goedbloed, M.H., Gardeniers, H.J.G.E., Verboom, W., Van Den Berg, A., Reinhoudt, D.N.
A MALDI-chip integrated system with a monitoring window
(2005) Lab on a Chip, 5 (4), pp. 378-381
DOI: 10.1039/b418986h

Mela, P., Tas, N.R., Berenschot, E.J.W., van Nieuwkasteele, J., van den Berg, A.
Electrokinetic pumping and detection of low-volume flows in nanochannels
(2004) Electrophoresis, 25 (21-22), pp. 3687-3693
DOI: 10.1002/elps.200406083

Tas, N.R., Haneveld, J., Jansen, H.V., Elwenspoek, M., Van Den Berg, A.
Capillary filling speed of water in nanochannels
(2004) Applied Physics Letters, 85 (15), pp. 3274-3276
DOI: 10.1063/1.1804602

Tas, N.R., Mela, P., Kramer, T., Berenschot, J.W., Van Den Berg, A.
Capillarity Induced Negative Pressure of Water Plugs in Nanochannels
(2003) Nano Letters, 3 (11), pp. 1537-1540.
DOI: 10.1021/nl034676e

Brivio, M., Fokkens, R.H., Verboom, W., Reinhoudt, D.N., Tas, N.R., Goedbloed, M., Van den Berg, A.
Integrated microfluidic system enabling (bio)chemical reactions with on-line MALDI-TOF mass spectrometry
(2002) Analytical Chemistry, 74 (16), pp. 3972-3976
DOI: 10.1021/ac020185n

Tas, N.R., Berenschot, J.W., Lammerink, T.S.J., Elwenspoek, M., Van den Berg, A.
Nanofluidic bubble pump using surface tension directed gas injection
(2002) Analytical Chemistry, 74 (9), pp. 2224-2227
DOI: 10.1021/ac011117o

Lammerink, T.S.J., Tas, N.R., Berenschot, J.W., Elwenspoek, M.C., Fluitman, J.H.J.
Micromachined hydraulic astable multivibrator
(1995) Proceedings of the IEEE Micro Electro Mechanical Systems, pp. 13-18

Adhesion, Stiction and Friction

Tas, N.R., Gui, C., Elwenspoek, M.
Static friction in elastic adhesion contacts in MEMS
(2003) Journal of Adhesion Science and Technology, 17 (4), pp. 547-561
DOI: 10.1163/15685610360554401

Blom, M.T., Tas, N.R., Pandraud, G., Chmela, E., Gardeniers, J.G.E., Tijssen, R., Elwenspoek, M., Van Den Berg, A.
Failure mechanisms of pressurized microchannels, model, and experiments
(2001) Journal of Microelectromechanical Systems, 10 (1), pp. 158-164
DOI: 10.1109/84.911105

Gui, C., Elwenspoek, M., Tas, N., Gardeniers, J.G.E.
The effect of surface roughness on direct wafer bonding
(1999) Journal of Applied Physics, 85 (10), pp. 7448-7454
DOI: 10.1063/1.369377

Tas, N., Sonnenberg, T., Jansen, H., Legtenberg, R., Elwenspoek, M.
Stiction in surface micromachining
(1996) Journal of Micromechanics and Microengineering, 6 (4), pp. 385-397
DOI: 10.1088/0960-1317/6/4/005 

Elastic Mechanics and Electrostatic / Thin Film Piezo Actuation

Sarajlic, E., Yamahata, C., Berenschot, E., Tas, N., Fujita, H., Krijnen, G.
High-performance shuffle motor fabricated by vertical trench isolation technology
(2010) Micromachines, 1 (2), pp. 48-67
DOI: 10.3390/mi1020048

Sarajlic, E., Berenschot, E., Tas, N., Fujita, H., Krijnen, G., Elwenspoek, M.
Fabrication and characterization of an electrostatic contraction beams micromotor
(2006) Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS), 2006, art. no. 1627924, pp. 814-817

Sarajlic, E., Berenschot, E., Tas, N., Fujita, H., Krijnen, G., Elwenspoek, M.
High performance bidirectional electrostatic inchworm motor fabricated by trench isolation technology
(2005) Digest of Technical Papers - International Conference on Solid State Sensors and Actuators and Microsystems, TRANSDUCERS '05, 1, art. no. 1C3.1, pp. 53-56

Tas, N.R., Sonnenberg, T., Molenaar, R., Elwenspoek, M.
Design, fabrication and testing of laterally driven electrostatic motors employing walking motion and mechanical leverage
(2003) Journal of Micromechanics and Microengineering, 13 (1), pp. N6-N15
DOI: 10.1088/0960-1317/13/1/402

Gardeniers, J.G.E., Verholen, A.G.B.J., Tas, N.R., Elwenspoek, M.
Direct measurement of piezoelectric properties of Sol-Gel PZT films
(1998) Journal of the Korean Physical Society, 32 (4 SUPPL.), pp. S1573-S1577

Tas, N., Wissink, J., Sander, L., Lammerink, T., Elwenspoek, M.
Modeling, design and testing of the electrostatic shuffle motor
(1998) Sensors and Actuators, A: Physical, 70 (1-2), pp. 171-178
DOI: 10.1016/S0924-4247(98)00129-0

Tas, N.R., Sonnenberg, A.H., Sander, A.F.M., Elwenspoek, M.C.
Surface micromachined linear electrostatic stepper motor
(1997) Proceedings of the IEEE Micro Electro Mechanical Systems (MEMS), pp. 215-220

Elasto-Capillarity

Legrain, A., Berenschot, E.J.W., Abelmann, L., Bico, J., Tas, N.R.
Let's twist again: Elasto-capillary assembly of parallel ribbons
(2016) Soft Matter, 12 (34), pp. 7186-7194
DOI: 10.1039/c6sm00910g

Legrain, A., Berenschot, J.W., Tas, N.R., Abelmann, L.
Capillary origami of micro-machined micro-objects: Bi-layer conductive hinges
(2015) Microelectronic Engineering, 140, pp. 60-66
DOI: 10.1016/j.mee.2015.06.004

Legrain, A., Janson, T.G., Berenschot, J.W., Abelmann, L., Tas, N.R.
Controllable elastocapillary folding of three-dimensional micro-objects by through-wafer filling
(2014) Journal of Applied Physics, 115 (21), art. no. 214905
DOI: 10.1063/1.4878460

Van Honschoten, J.W., Berenschot, J.W., Ondaŗuhu, T., Sanders, R.G.P., Sundaram, J., Elwenspoek, M., Tas, N.R.
Elastocapillary fabrication of three-dimensional microstructures
(2010) Applied Physics Letters, 97 (1), art. no. 014103
DOI: 10.1063/1.3462302

Tas, N.R., Escalante, M., Van Honschoten, J.W., Jansen, H.V., Elwenspoek, M.
Capillary negative pressure measured by nanochannel collapse
(2010) Langmuir, 26 (3), pp. 1473-1476
DOI: 10.1021/la903649n

van Honschoten, J.W., Tas, N.R., Elwenspoek, M.
The profile of a capillary liquid bridge between solid surfaces
(2010) American Journal of Physics, 78 (3), art. no. 012002AJP, pp. 277-286
DOI: 10.1119/1.3273854

van Honschoten, J.W., Escalante, M., Tas, N.R., Elwenspoek, M.
Formation of liquid menisci in flexible nanochannels
(2009) Journal of Colloid and Interface Science, 329 (1), pp. 133-139
DOI: 10.1016/j.jcis.2008.09.082 

Fluidic SPM

Geerlings, J., Sarajlic, E., Berenschot, E.J.W., Sanders, R.G.P., Siekman, M.H., Abelmann, L., Tas, N.R.
Electric field controlled nanoscale contactless deposition using a nanofluidic scanning probe
(2015) Applied Physics Letters, 107 (12), art. no. 123109
DOI: 10.1063/1.4931354

Deladi, S., Tas, N.R., Berenschot, J.W., De Boer, J.H., De Boer, M.J., Krijnen, G.J.M., Elwenspoek, M.C.
Micromachined fountain pen as a tool for atomic force microscope-based nanoelectrochemical metal deposition
(2005) Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS), art. no. TPb35, pp. 564-567
ISSN: 10846999

Deladi, S., Berenschot, J.W., Tas, N.R., Krijnen, G.J.M., De Boer, J.H., De Boer, M.J., Elwenspoek, M.C.
Fabrication of micromachined fountain pen with in situ characterization possibility of nanoscale surface modification
(2005) Journal of Micromechanics and Microengineering, 15 (3), pp. 528-534
DOI: 10.1088/0960-1317/15/3/013

Deladi, S., Tas, N.R., Berenschot, J.W., Krijnen, G.J.M., De Boer, M.J., De Boer, J.H., Peter, M., Elwenspoek, M.C.
Micromachined fountain pen for atomic force microscope-based nanopatterning
(2004) Applied Physics Letters, 85 (22), art. no. 3, pp. 5361-5363
DOI: 10.1063/1.1823040

Acoustic Resonators

Yagubizade, H., Darvishi, M., Elwenspoek, M.C., Tas, N.R.
A 4th-order band-pass filter using differential readout of two in-phase actuated contour-mode resonators
(2013) Applied Physics Letters, 103 (17), art. no. 173517
DOI: 10.1109/MEMSYS.2014.6765872

Yagubizade, H., Darvishi, M., Chen, Y.-Y., Nguyen, M.D., Dekkers, J.M., Wiegerink, R.J., Elwenspoek, M.C., Tas, N.R.
Pulsed-laser deposited Pb(Zr0.52,Ti0.48)O 3-on-silicon resonators with high-stopband rejection using feed-through cancellation
(2013) Applied Physics Letters, 102 (6), art. no. 063509
DOI: 10.1063/1.4792739 

Flow Sensing

Lammerink, T.S.J., Tas, N.R., Krijnen, G.J.M., Elwenspoek, M.
New class of thermal flow sensors using ΔT = 0 as a control signal
(2000) Proceedings of the IEEE Micro Electro Mechanical Systems (MEMS), pp. 525-530

Lammerink, T.S.J., Tas, N.R., Elwenspoek, M., Fluitman, J.H.J.
Micro-liquid flow sensor
(1993) Sensors and Actuators: A. Physical, 37-38 (C), pp. 45-50
DOI: 10.1016/0924-4247(93)80010-E