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Prof. Ulrich Schmid
Institute of Sensor and Actuator Systems, TU Wien, Vienna 1040, Austria

Basic Info

Basic Info is private.

Research Keywords & Expertise

0 Material Characterization
0 PiezoMEMS
0 MEMS (e.g. sensors, actuators)
0 SiCMEMS
0 MEMS materials (e.g. SiC, AlN, ScAlN, PVDF)

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Journal article
Published: 08 April 2021 in Electrochem
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Ti/Au multi-layered micro-cantilevers with complex three-dimensional structures used as micro-components in micro-electromechanical systems (MEMS) sensors were prepared by lithography and electrodeposition, and the effective Young’s modulus was evaluated by the resonance frequency method and finite element method simulation. Effects of the constraint condition at the fixed-end of the micro-cantilever and the temperature dependency of the effective Young’s modulus were studied. Three types of the constraint at the fixed-end were prepared, which were normal type (constraining only bottom surface of the fixed-end), block type (constraining both top and bottom surfaces), and bridge type (top surfaces covering with a bridge-like structure). The temperature dependency test was conducted in a temperature range from 150 to 300 °C in a vacuum chamber. An increase in the effective Young’s modulus was observed as the constraint condition became more rigid, and the effective Young’s modulus merely changed as the temperature varied from room temperature to 300 °C.

ACS Style

Hitomi Watanabe; Tso-Fu Chang; Michael Schneider; Ulrich Schmid; Chun-Yi Chen; Shinichi Iida; Daisuke Yamane; Hiroyuki Ito; Katsuyuki Machida; Kazuya Masu; Masato Sone. Effective Young’s Modulus of Complex Three Dimensional Multilayered Ti/Au Micro-Cantilevers Fabricated by Electrodeposition and the Temperature Dependency. Electrochem 2021, 2, 216 -223.

AMA Style

Hitomi Watanabe, Tso-Fu Chang, Michael Schneider, Ulrich Schmid, Chun-Yi Chen, Shinichi Iida, Daisuke Yamane, Hiroyuki Ito, Katsuyuki Machida, Kazuya Masu, Masato Sone. Effective Young’s Modulus of Complex Three Dimensional Multilayered Ti/Au Micro-Cantilevers Fabricated by Electrodeposition and the Temperature Dependency. Electrochem. 2021; 2 (2):216-223.

Chicago/Turabian Style

Hitomi Watanabe; Tso-Fu Chang; Michael Schneider; Ulrich Schmid; Chun-Yi Chen; Shinichi Iida; Daisuke Yamane; Hiroyuki Ito; Katsuyuki Machida; Kazuya Masu; Masato Sone. 2021. "Effective Young’s Modulus of Complex Three Dimensional Multilayered Ti/Au Micro-Cantilevers Fabricated by Electrodeposition and the Temperature Dependency." Electrochem 2, no. 2: 216-223.

Journal article
Published: 09 November 2018 in Sensors
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In atomic force microscopes (AFM) a resonantly excited, micro-machined cantilever with a tip is used for sensing surface-related properties. When targeting the integration of AFMs into vacuum environments (e.g., for enhancing the performance of scanning electron microscopes), a tuneable Q-factor of the resonating AFM cantilever is a key feature to enable high speed measurements with high local resolution. To achieve this goal, in this study an additional mechanical stimulus is applied to the cantilever with respect to the stimulus provided by the macroscopic piezoelectric actuator. This additional stimulus is generated by an aluminum nitride piezoelectric thin film actuator integrated on the cantilever, which is driven by a phase shifted excitation. The Q-factor is determined electrically by the piezoelectric layer in a Wheatstone bridge configuration and optically verified in parallel with a laser Doppler vibrometer. Depending on the measurement technique, the Q-factor is reduced by a factor of about 1.9 (electrically) and 1.6 (optically), thus enabling the damping of MEMS structures with a straight-forward and cheap electronic approach.

ACS Style

Martin Fischeneder; Martin Oposich; Michael Schneider; Ulrich Schmid. Tuneable Q-Factor of MEMS Cantilevers with Integrated Piezoelectric Thin Films. Sensors 2018, 18, 3842 .

AMA Style

Martin Fischeneder, Martin Oposich, Michael Schneider, Ulrich Schmid. Tuneable Q-Factor of MEMS Cantilevers with Integrated Piezoelectric Thin Films. Sensors. 2018; 18 (11):3842.

Chicago/Turabian Style

Martin Fischeneder; Martin Oposich; Michael Schneider; Ulrich Schmid. 2018. "Tuneable Q-Factor of MEMS Cantilevers with Integrated Piezoelectric Thin Films." Sensors 18, no. 11: 3842.

Journal article
Published: 05 June 2018 in Journal of The Electrochemical Society
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In this paper the pore formation process during metal assisted photochemical etching (MAPCE) of 4H silicon carbide (SiC) is investigated. By utilizing cellular automaton simulations, it was found, that MAPCE can be described by time-stochastic effects as long as the etching rate is constant. When this is not the case, other effects such as the growth of already existing pores dominate, and the probability of new pore formation decreases. These findings implied that porous SiC generated with MAPCE can most beneficially be used as anti- reflective coating or as integrated filter element in optical sensor applications.

ACS Style

Markus Leitgeb; Christopher Zellner; Markus Lukschanderl; Michael Schneider; Ulrich Schmid. Editors' Choice—A Cellular Automaton Based Interpretation of Metal Assisted Photochemical Porosification of 4H Silicon Carbide. Journal of The Electrochemical Society 2018, 165, E325 -E329.

AMA Style

Markus Leitgeb, Christopher Zellner, Markus Lukschanderl, Michael Schneider, Ulrich Schmid. Editors' Choice—A Cellular Automaton Based Interpretation of Metal Assisted Photochemical Porosification of 4H Silicon Carbide. Journal of The Electrochemical Society. 2018; 165 (9):E325-E329.

Chicago/Turabian Style

Markus Leitgeb; Christopher Zellner; Markus Lukschanderl; Michael Schneider; Ulrich Schmid. 2018. "Editors' Choice—A Cellular Automaton Based Interpretation of Metal Assisted Photochemical Porosification of 4H Silicon Carbide." Journal of The Electrochemical Society 165, no. 9: E325-E329.

Accepted manuscript
Published: 01 June 2018 in Materials Research Express
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MEMS (micro electro-mechanical systems) operated in resonance and excited piezoelectrically are nowadays used for a broad range of different application scenarios. To enhance the process stability and hence, the reproducibility of key film parameters of sputter-deposited aluminium nitride such as the film stress, the piezoelectric coefficient d33 and low leakage current levels, a novel aluminium clamped substrate holder is reported. Compared to the standard molybdenum based solution, where the thermal contact between the wafer and substrate holder varies during deposition, as the wafer can move freely, the substrate temperature variations are substantially reduced due to clamped configuration. Independent of AlN film thickness ranging between 0.5 µm and 2.0 µm the scatter in piezoelectric constant d33 and leakage current characteristics represented by the barrier height and the activation energy is reduced up to a factor of 3. These results demonstrate the importance to control carefully the temperature conditions during low-temperature AlN deposition to ensure a high reproducibility in film properties.

ACS Style

Martin Fischeneder; Achim Bittner; Michael Schneider; Ulrich Schmid. Enhanced process stability for the low temperature sputter deposition of aluminium nitride thin films. Materials Research Express 2018, 5, 066412 .

AMA Style

Martin Fischeneder, Achim Bittner, Michael Schneider, Ulrich Schmid. Enhanced process stability for the low temperature sputter deposition of aluminium nitride thin films. Materials Research Express. 2018; 5 (6):066412.

Chicago/Turabian Style

Martin Fischeneder; Achim Bittner; Michael Schneider; Ulrich Schmid. 2018. "Enhanced process stability for the low temperature sputter deposition of aluminium nitride thin films." Materials Research Express 5, no. 6: 066412.

Editorial
Published: 15 May 2018 in Micromachines
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Note: In lieu of an abstract, this is an excerpt from the first page.Excerpt Electromechanical transducers that utilize the piezoelectric effect have been increasingly used in micro-electromechanical systems (MEMS) either as substrates or as thin films

ACS Style

Ulrich Schmid; Michael Schneider. Editorial for the Special Issue on Piezoelectric MEMS. Micromachines 2018, 9, 237 .

AMA Style

Ulrich Schmid, Michael Schneider. Editorial for the Special Issue on Piezoelectric MEMS. Micromachines. 2018; 9 (5):237.

Chicago/Turabian Style

Ulrich Schmid; Michael Schneider. 2018. "Editorial for the Special Issue on Piezoelectric MEMS." Micromachines 9, no. 5: 237.

Journal article
Published: 01 May 2018 in Journal of the European Ceramic Society
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The demand to meet advanced substrate requirements in terms of electrical, mechanical, thermal, and dielectric properties has led to an increasing interest in low temperature co-fired ceramics (LTCC). However, LTCC materials suffer from high permittivity. We recently showed that the wet-chemical porosification under acidic conditions allows the reduction of the permittivity of LTCCs in the as-fired state. In the present study, potassium hydroxide solution was employed as an alternative etchant which features a suitable bearing plane for further metallization lines. Various characterization techniques, including scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, and electron energy loss spectroscopy were used for investigation of the morphology and chemical composition of the substrates. Three-dimensional information of the surface topography was acquired by means of MeX® Alicona software and the obtained roughness parameters confirmed the advantage of the proposed approach over acid treatment when targeting an enhanced surface quality.

ACS Style

Ali Hajian; Michael Stöger-Pollach; Michael Schneider; Doruk Müftüoglu; Frank K. Crunwell; Ulrich Schmid. Porosification behaviour of LTCC substrates with potassium hydroxide. Journal of the European Ceramic Society 2018, 38, 2369 -2377.

AMA Style

Ali Hajian, Michael Stöger-Pollach, Michael Schneider, Doruk Müftüoglu, Frank K. Crunwell, Ulrich Schmid. Porosification behaviour of LTCC substrates with potassium hydroxide. Journal of the European Ceramic Society. 2018; 38 (5):2369-2377.

Chicago/Turabian Style

Ali Hajian; Michael Stöger-Pollach; Michael Schneider; Doruk Müftüoglu; Frank K. Crunwell; Ulrich Schmid. 2018. "Porosification behaviour of LTCC substrates with potassium hydroxide." Journal of the European Ceramic Society 38, no. 5: 2369-2377.

Proceedings
Published: 16 January 2018 in Proceedings
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This study reports on a novel bi-stable actuator with an integrated aluminum nitride (AlN) piezoelectric layer sandwiched between two electrodes. To achieve bistability, the membranes must exceed a characteristic compressive stress value, also called the critical stress. For this purpose, we used highly c-axis orientated stress-controlled AlN with a thickness of 400 nm. First experiments showed, that it is possible to switch between the two stable ground states with at least two rectangular pulses at a frequency of 80 kHz and with a voltage Vpp of 40 V, resulting in a displacement of about 10 µm for each switching direction.

ACS Style

Manuel Dorfmeister; Bernhard Kössl; Michael Schneider; Ulrich Schmid. A Novel Bi-Stable MEMS Membrane Concept Based on a Piezoelectric Thin Film Actuator for Integrated Switching. Proceedings 2018, 2, 912 .

AMA Style

Manuel Dorfmeister, Bernhard Kössl, Michael Schneider, Ulrich Schmid. A Novel Bi-Stable MEMS Membrane Concept Based on a Piezoelectric Thin Film Actuator for Integrated Switching. Proceedings. 2018; 2 (13):912.

Chicago/Turabian Style

Manuel Dorfmeister; Bernhard Kössl; Michael Schneider; Ulrich Schmid. 2018. "A Novel Bi-Stable MEMS Membrane Concept Based on a Piezoelectric Thin Film Actuator for Integrated Switching." Proceedings 2, no. 13: 912.

Proceedings
Published: 01 January 2018 in Proceedings
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In preliminary studies it could be shown that single crystalline silicon carbide wafers can be porosified with metal assisted photochemical etching. Furthermore, the generation of porous areas which are locally defined is possible with this method. By adjusting the etching parameters, a highly porous layer (degree of porosity of 90%) can be formed which is under-etched by a line of breakage. By depositing a compressively stressed amorphous SiC:H thin film on top of a porous region, the a-SiC:H film can be locally separated from the substrate, resulting in a buckled membrane configuration. Such membranes might open up potential applications in MEMS design concepts.

ACS Style

Markus Leitgeb; Christopher Zellner; Manuel Dorfmeister; Michael Schneider; Ulrich Schmid. Buckling Porous SiC Membranes. Proceedings 2018, 2, 785 .

AMA Style

Markus Leitgeb, Christopher Zellner, Manuel Dorfmeister, Michael Schneider, Ulrich Schmid. Buckling Porous SiC Membranes. Proceedings. 2018; 2 (13):785.

Chicago/Turabian Style

Markus Leitgeb; Christopher Zellner; Manuel Dorfmeister; Michael Schneider; Ulrich Schmid. 2018. "Buckling Porous SiC Membranes." Proceedings 2, no. 13: 785.

Proceedings
Published: 01 January 2018 in Proceedings
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Recently, organic electromechanical transducers have attracted intense scientific and technological interest due to their unique mechanical flexibility and their piezoelectric properties. However, the fabrication of organic MEMS devices is challenging. For example, a lift-off process cannot be used on polymers, because of the solvent in photoresists. Here, we present a straightforward and low-cost batch process for organic MEMS devices using standard micromachining techniques. As organic material we used the ferroelectric (co-)polymer poly(vinylidene fluoride-trifluorethylene) (P(VDF-TrFE)). The integration of the polymer in a CMOS-compatible process was optimized in terms of deposition and patterning of the polymer and the corresponding metal layers. Micromachined devices, such as capacitors and cantilevers, were fabricated and analysed. The ferroelectric perfomance was evaluated by electrical and electromechanical measurements. Our first results indicate that the proposed fabrication process is reliable resulting in well-functioning organic MEMS devices. We measured as piezoelectric constant a d33 of −32 pm/V with our organic P(VDF-TrFE) capacitors.

ACS Style

Jonas Hafner; Marco Teuschel; Jürgen Schrattenholzer; Michael Schneider; Ulrich Schmid. Optimized Batch Process for Organic MEMS Devices. Proceedings 2018, 2, 904 .

AMA Style

Jonas Hafner, Marco Teuschel, Jürgen Schrattenholzer, Michael Schneider, Ulrich Schmid. Optimized Batch Process for Organic MEMS Devices. Proceedings. 2018; 2 (13):904.

Chicago/Turabian Style

Jonas Hafner; Marco Teuschel; Jürgen Schrattenholzer; Michael Schneider; Ulrich Schmid. 2018. "Optimized Batch Process for Organic MEMS Devices." Proceedings 2, no. 13: 904.

Proceedings
Published: 01 January 2018 in Proceedings
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We present a novel MEMS sensor for the detection of magnetic particles in liquids, which consists of a microcantilever excited piezoelectrically in resonance and having an integrated planar coil on its free end. Due to the latter component, magnetic particles are attracted and accumulate on the sensor surface. The additional mass introduced by the particles changes the resonance frequency of the microcantilever serving as measured quantity. To evaluate our design, we dispersed 250 nm iron-oxide particles in de-ionized water and monitored the resonance frequency during particle accumulation. 100 min after measurement start, a total resonance frequency shift of 6 kHz was found, which can easily be measured and shows the high potential of the proposed sensor design.

ACS Style

Florian Patocka; Matthias Schlögl; Michael Schneider; Ulrich Schmid. Novel MEMS Sensor for Detecting Magnetic Particles in Liquids. Proceedings 2018, 2, 868 .

AMA Style

Florian Patocka, Matthias Schlögl, Michael Schneider, Ulrich Schmid. Novel MEMS Sensor for Detecting Magnetic Particles in Liquids. Proceedings. 2018; 2 (13):868.

Chicago/Turabian Style

Florian Patocka; Matthias Schlögl; Michael Schneider; Ulrich Schmid. 2018. "Novel MEMS Sensor for Detecting Magnetic Particles in Liquids." Proceedings 2, no. 13: 868.

Proceedings
Published: 01 January 2018 in Proceedings
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Resonant micro- and nanoelectromechanical systems (MEMS/NEMS) are typically subject to interaction with a liquid or gaseous environment. Recently, it has been demonstrated that non-conventional eigenmodes exhibit remarkably high quality factors (Q factors) in liquids. However, the physical origin of this phenomenon remains elusive. Here we introduce a definition of non-conventional eigenmodes for cantilever structures and develop a boundary integral method for describing the interaction of an incompressible viscous fluid and a non-conventional eigenmode of a MEMS/NEMS resonator. With this framework we are able to study the influence of the mode shape on the fluid-structure interaction.

ACS Style

Daniel Platz; Georg Pfusterschmied; Ulrich Schmid. Modelling Fluid Damping of Non-Conventional Vibration Modes in MEMS Resonators. Proceedings 2018, 2, 896 .

AMA Style

Daniel Platz, Georg Pfusterschmied, Ulrich Schmid. Modelling Fluid Damping of Non-Conventional Vibration Modes in MEMS Resonators. Proceedings. 2018; 2 (13):896.

Chicago/Turabian Style

Daniel Platz; Georg Pfusterschmied; Ulrich Schmid. 2018. "Modelling Fluid Damping of Non-Conventional Vibration Modes in MEMS Resonators." Proceedings 2, no. 13: 896.

Journal article
Published: 18 December 2017 in Applied Physics Letters
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We report on the detection of free nanoparticles in a micromachined, open-access Fabry-Pérot microcavity. With a mirror separation of 130 μm, a radius of curvature of 1.3 mm, and a beam waist of 12 μm, the mode volume of our symmetric infrared cavity is smaller than 15 pL. The small beam waist, together with a finesse exceeding 34 000, enables the detection of nanoscale dielectric particles in high vacuum. This device allows monitoring of the motion of individual 150 nm radius silica nanospheres in real time. We observe strong coupling between the particles and the cavity field, a precondition for optomechanical control. We discuss the prospects for optical cooling and detection of dielectric particles smaller than 10 nm in radius and 1 × 107 amu in mass.

ACS Style

Stefan Kuhn; Georg Wachter; Franz-Ferdinand Wieser; James Millen; Michael Schneider; Johannes Schalko; Ulrich Schmid; Michael Trupke; Markus Arndt. Nanoparticle detection in an open-access silicon microcavity. Applied Physics Letters 2017, 111, 253107 .

AMA Style

Stefan Kuhn, Georg Wachter, Franz-Ferdinand Wieser, James Millen, Michael Schneider, Johannes Schalko, Ulrich Schmid, Michael Trupke, Markus Arndt. Nanoparticle detection in an open-access silicon microcavity. Applied Physics Letters. 2017; 111 (25):253107.

Chicago/Turabian Style

Stefan Kuhn; Georg Wachter; Franz-Ferdinand Wieser; James Millen; Michael Schneider; Johannes Schalko; Ulrich Schmid; Michael Trupke; Markus Arndt. 2017. "Nanoparticle detection in an open-access silicon microcavity." Applied Physics Letters 111, no. 25: 253107.

Preprint
Published: 05 December 2017
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We report on the detection of free nanoparticles in a micromachined, open-access Fabry-P\'erot microcavity. With a mirror separation of $130\,\mu$m, a radius of curvature of $1.3\,$mm, and a beam waist of $12\,\mu$m, the mode volume of our symmetric infrared cavity is smaller than $15\,$pL. The small beam waist, together with a finesse exceeding 34,000, enables the detection of nano-scale dielectric particles in high vacuum. This device allows monitoring of the motion of individual $150\,$nm radius silica nanospheres in real time. We observe strong coupling between the particles and the cavity field, a precondition for optomechanical control. We discuss the prospects for optical cooling and detection of dielectric particles smaller than $10\,$nm in radius and $1\times10^7\,$amu in mass.

ACS Style

Stefan Kühn; Georg Wachter; Franz-Ferdinand Wieser; James Millen; Michael Schneider; Johannes Schalko; Ulrich Schmid; Michael Trupke; Markus Arndt. Nanoparticle detection in an open-access silicon microcavity. 2017, 1 .

AMA Style

Stefan Kühn, Georg Wachter, Franz-Ferdinand Wieser, James Millen, Michael Schneider, Johannes Schalko, Ulrich Schmid, Michael Trupke, Markus Arndt. Nanoparticle detection in an open-access silicon microcavity. . 2017; ():1.

Chicago/Turabian Style

Stefan Kühn; Georg Wachter; Franz-Ferdinand Wieser; James Millen; Michael Schneider; Johannes Schalko; Ulrich Schmid; Michael Trupke; Markus Arndt. 2017. "Nanoparticle detection in an open-access silicon microcavity." , no. : 1.

Conference paper
Published: 14 November 2017 in Proceedings of 4th International Electronic Conference on Sensors and Applications
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My talk is divided into three parts: First, I will give a short introduction to the Institute of Sensor and Actuator Systems, our infrastructure and our expertise in the field of micro- and nanomachined devices and systems. In the second part of my talk, piezoelectric thin films are introduced for MEMS. I will highlight latest results on the electrical, mechanical and piezoelectrical characterization of sputter-deposited aluminium nitride (AlN) including the impact of sputter parameters, film thickness and substrate pre-conditioning. To enhance the moderate piezoelectric coefficients of pure AlN thin films doping with scandium is done leading to an increase of this material parameter up to factor of 4. In a next step, these films are implemented into the fabrication process of cantilever-type MEMS devices. In combination with a tailored electrode design resonators are realized having Q factors up to about 300 in the frequency range of 1-2 MHz in liquids, thus enabling the precise determination of the viscosity and density of fluids. An additional field of application are vibrational energy harvesters, where the benefit of ScAlN compared to AlN is demonstrated. In the third part of the talk energy harvesting at aircrafts is introduced. Due to the ambient conditions during operation a thermoelectric generator is developed providing enough electrical energy to power wireless sensor nodes for structural health monitoring purposes. The basic concept of the energy harvester as well as first results from flight tests are presented.

ACS Style

Ulrich Schmid; Michael Schneider. Piezoelectric Microsystems: Material Aspects, Devices and Applications. Proceedings of 4th International Electronic Conference on Sensors and Applications 2017, 4934 .

AMA Style

Ulrich Schmid, Michael Schneider. Piezoelectric Microsystems: Material Aspects, Devices and Applications. Proceedings of 4th International Electronic Conference on Sensors and Applications. 2017; ():4934.

Chicago/Turabian Style

Ulrich Schmid; Michael Schneider. 2017. "Piezoelectric Microsystems: Material Aspects, Devices and Applications." Proceedings of 4th International Electronic Conference on Sensors and Applications , no. : 4934.

Journal article
Published: 18 October 2017 in Micromachines
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Fully implantable, self-powered hearing aids with no external unit could significantly increase the life quality of patients suffering severe hearing loss. This highly demanding concept, however, requires a strongly miniaturized device which is fully implantable in the middle/inner ear and includes the following components: frequency selective microphone or accelerometer, energy harvesting device, speech processor, and cochlear multielectrode. Here we demonstrate a low volume, piezoelectric micro-electromechanical system (MEMS) cantilever array which is sensitive, even in the lower part of the voice frequency range (300–700 Hz). The test array consisting of 16 cantilevers has been fabricated by standard bulk micromachining using a Si-on-Insulator (SOI) wafer and aluminum nitride (AlN) as a complementary metal-oxide-semiconductor (CMOS) and biocompatible piezoelectric material. The low frequency and low device footprint are ensured by Archimedean spiral geometry and Si seismic mass. Experimentally detected resonance frequencies were validated by an analytical model. The generated open circuit voltage (3–10 mV) is sufficient for the direct analog conversion of the signals for cochlear multielectrode implants.

ACS Style

Péter Udvardi; János Radó; András Straszner; János Ferencz; Zoltán Hajnal; Saeedeh Soleimani; Michael Schneider; Ulrich Schmid; Péter Révész; János Volk. Spiral-Shaped Piezoelectric MEMS Cantilever Array for Fully Implantable Hearing Systems. Micromachines 2017, 8, 311 .

AMA Style

Péter Udvardi, János Radó, András Straszner, János Ferencz, Zoltán Hajnal, Saeedeh Soleimani, Michael Schneider, Ulrich Schmid, Péter Révész, János Volk. Spiral-Shaped Piezoelectric MEMS Cantilever Array for Fully Implantable Hearing Systems. Micromachines. 2017; 8 (10):311.

Chicago/Turabian Style

Péter Udvardi; János Radó; András Straszner; János Ferencz; Zoltán Hajnal; Saeedeh Soleimani; Michael Schneider; Ulrich Schmid; Péter Révész; János Volk. 2017. "Spiral-Shaped Piezoelectric MEMS Cantilever Array for Fully Implantable Hearing Systems." Micromachines 8, no. 10: 311.

Journal article
Published: 26 June 2017 in Micromachines
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In this study grape must fermentation is monitored using a self-actuating/self-sensing piezoelectric micro-electromechanical system (MEMS) resonator. The sensor element is excited in an advanced roof tile-shaped vibration mode, which ensures high Q-factors in liquids (i.e., Q ~100 in isopropanol), precise resonance frequency analysis, and a fast measurement procedure. Two sets of artificial model solutions are prepared, representing an ordinary and a stuck/sluggish wine fermentation process. The precision and reusability of the sensor are shown using repetitive measurements (10 times), resulting in standard deviations of the measured resonance frequencies of ~0.1%, Q-factor of ~11%, and an electrical conductance peak height of ~12%, respectively. With the applied evaluation procedure, moderate standard deviations of ~1.1% with respect to density values are achieved. Based on these results, the presented sensor concept is capable to distinguish between ordinary and stuck wine fermentation, where the evolution of the wine density associated with the decrease in sugar and the increase in ethanol concentrations during fermentation processes causes a steady increase in the resonance frequency for an ordinary fermentation. Finally, the first test measurements in real grape must are presented, showing a similar trend in the resonance frequency compared to the results of an artificial solutions, thus proving that the presented sensor concept is a reliable and reusable platform for grape must fermentation monitoring.

ACS Style

Georg Pfusterschmied; Javier Toledo; Martin Kucera; Wolfgang Steindl; Stefan Zemann; Víctor Ruiz-Díez; Michael Schneider; Achim Bittner; Jose Luis Sanchez-Rojas; Ulrich Schmid. Potential of Piezoelectric MEMS Resonators for Grape Must Fermentation Monitoring. Micromachines 2017, 8, 200 .

AMA Style

Georg Pfusterschmied, Javier Toledo, Martin Kucera, Wolfgang Steindl, Stefan Zemann, Víctor Ruiz-Díez, Michael Schneider, Achim Bittner, Jose Luis Sanchez-Rojas, Ulrich Schmid. Potential of Piezoelectric MEMS Resonators for Grape Must Fermentation Monitoring. Micromachines. 2017; 8 (7):200.

Chicago/Turabian Style

Georg Pfusterschmied; Javier Toledo; Martin Kucera; Wolfgang Steindl; Stefan Zemann; Víctor Ruiz-Díez; Michael Schneider; Achim Bittner; Jose Luis Sanchez-Rojas; Ulrich Schmid. 2017. "Potential of Piezoelectric MEMS Resonators for Grape Must Fermentation Monitoring." Micromachines 8, no. 7: 200.

Journal article
Published: 03 June 2017 in Actuators
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In this paper, two different piezoelectric microactuator designs are studied. The corresponding devices were designed for optimal in-plane displacements and different high flexibilities, proven by electrical and optical characterization. Both actuators presented two dominant vibrational modes in the frequency range below 1 MHz: an out-of-plane bending and an in-plane extensional mode. Nevertheless, the latter mode is the only one that allows the use of the device as a modal in-plane actuator. Finite Element Method (FEM) simulations confirmed that the displacement per applied voltage was superior for the low-stiffness actuator, which was also verified through optical measurements in a quasi-static analysis, obtaining a displacement per volt of 0.22 and 0.13 nm/V for the low-stiffness and high-stiffness actuator, respectively. In addition, electrical measurements were performed using an impedance analyzer which, in combination with the optical characterization in resonance, allowed the determination of the electromechanical and stiffness coefficients. The low-stiffness actuator exhibited a stiffness coefficient of 5 × 104 N/m, thus being more suitable as a modal actuator than the high-stiffness actuator with a stiffness of 2.5 × 105 N/m.

ACS Style

Javier Toledo; Victor Ruiz-Díez; Alex Diaz-Molina; David Ruiz; Alberto Donoso; José Carlos Bellido; Elisabeth Wistrela; Martin Kucera; Ulrich Schmid; Jorge Hernando-García; José Luis Sánchez-Rojas; Alex Díaz. Design and Characterization of In-Plane Piezoelectric Microactuators. Actuators 2017, 6, 19 .

AMA Style

Javier Toledo, Victor Ruiz-Díez, Alex Diaz-Molina, David Ruiz, Alberto Donoso, José Carlos Bellido, Elisabeth Wistrela, Martin Kucera, Ulrich Schmid, Jorge Hernando-García, José Luis Sánchez-Rojas, Alex Díaz. Design and Characterization of In-Plane Piezoelectric Microactuators. Actuators. 2017; 6 (2):19.

Chicago/Turabian Style

Javier Toledo; Victor Ruiz-Díez; Alex Diaz-Molina; David Ruiz; Alberto Donoso; José Carlos Bellido; Elisabeth Wistrela; Martin Kucera; Ulrich Schmid; Jorge Hernando-García; José Luis Sánchez-Rojas; Alex Díaz. 2017. "Design and Characterization of In-Plane Piezoelectric Microactuators." Actuators 6, no. 2: 19.

Proceedings
Published: 01 January 2017 in Proceedings
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Metal assisted photochemical etching (MAPCE) of 4H Silicon Carbide (SiC) was utilized to generate locally defined porous areas on single crystalline substrates. Therefore, Platinum (Pt) was sputter deposited on 4H-SiC substrates and patterned with photolithography and lift off. Etching was performed by immersing the Pt coated samples into an etching solution containing sodium persulphate and hydrofluoric acid. UV light irradiation was necessary for charge carrier generation while the Pt served as local cathode. The generated porous areas can be used for the generation of integrated cavities in the single crystalline SiC substrates when covered with a chemical vapor deposited thin film of poly-crystalline SiC.

ACS Style

Markus Leitgeb; Christopher Zellner; Georg Pfusterschmied; Michael Schneider; Ulrich Schmid. Porous Silicon Carbide for MEMS. Proceedings 2017, 1, 297 .

AMA Style

Markus Leitgeb, Christopher Zellner, Georg Pfusterschmied, Michael Schneider, Ulrich Schmid. Porous Silicon Carbide for MEMS. Proceedings. 2017; 1 (4):297.

Chicago/Turabian Style

Markus Leitgeb; Christopher Zellner; Georg Pfusterschmied; Michael Schneider; Ulrich Schmid. 2017. "Porous Silicon Carbide for MEMS." Proceedings 1, no. 4: 297.

Proceedings
Published: 01 January 2017 in Proceedings
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When targeting the integration of atomic force microscopes (AFM) into vacuum environments (e.g., scanning electron microscopes), a tunable Q-factor of the resonating AFM cantilever is a key feature to enable high speed measurements with high local resolution. To achieve this goal, an additional stimulus is applied to the cantilever with respect to the mechanical stimulus provided by the macroscopic piezoelectric actuator. This additional stimulus is generated by an aluminium nitride based piezoelectric actuator integrated on the cantilever, which is driven by a phase shifted excitation. With this approach, the mechanical Q-factor measured with a laser Doppler vibrometer (LDV) in vacuum is electrically decreased by a factor of up to 1.7.

ACS Style

Martin Fischeneder; Martin Oposich; Michael Schneider; Ulrich Schmid. Tuneable Q-Factor of MEMS Cantilevers with Integrated Piezoelectric Thin Films. Proceedings 2017, 1, 380 .

AMA Style

Martin Fischeneder, Martin Oposich, Michael Schneider, Ulrich Schmid. Tuneable Q-Factor of MEMS Cantilevers with Integrated Piezoelectric Thin Films. Proceedings. 2017; 1 (4):380.

Chicago/Turabian Style

Martin Fischeneder; Martin Oposich; Michael Schneider; Ulrich Schmid. 2017. "Tuneable Q-Factor of MEMS Cantilevers with Integrated Piezoelectric Thin Films." Proceedings 1, no. 4: 380.

Proceedings
Published: 01 January 2017 in Proceedings
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Film bulk acoustic resonators (FBAR) are promising candidates to replace surface acoustic wave devices as filters or delay lines, but also offer exciting opportunities as biological or gas sensors. In this work, solidly mounted FBARs were manufactured by substituting commonly used pure aluminium nitride (AlN) by scandium doped aluminium nitride (ScAlN) thin films as the piezoelectric layer. The ScAlN-based resonators feature a significant improvement of the electromechanical coupling factor from ~3% to ~12% compared to the pure AlN, while the decreased stiffness of ScAlN results in a decrease of the quality factor from ~300 to ~100 due to increased damping losses in the piezoelectric material.

ACS Style

Michael Schneider; Mario DeMiguel-Ramos; Andrew J. Flewitt; Enrique Iborra; Ulrich Schmid. Scandium Aluminium Nitride-Based Film Bulk Acoustic Resonators. Proceedings 2017, 1, 305 .

AMA Style

Michael Schneider, Mario DeMiguel-Ramos, Andrew J. Flewitt, Enrique Iborra, Ulrich Schmid. Scandium Aluminium Nitride-Based Film Bulk Acoustic Resonators. Proceedings. 2017; 1 (4):305.

Chicago/Turabian Style

Michael Schneider; Mario DeMiguel-Ramos; Andrew J. Flewitt; Enrique Iborra; Ulrich Schmid. 2017. "Scandium Aluminium Nitride-Based Film Bulk Acoustic Resonators." Proceedings 1, no. 4: 305.