Thermomechanical noise - Dennis Alveringh - Salland Engineering
Abstract: Thermomechanical noise in micromachined sensors: the fundamental specification for MEMS test equipment?
Thermomechanical noise causes random vibrations in resonators. As many sensors consist of a mechanical mass-spring-damper system, the thermomechanical noise defines a fundamental limit to the sensor's resolution. This effect has been modeled using the equipartition theorem and validated in an experimental laser Doppler vibrometry setup for a large range of temperatures. This is probably quite interesting from an academic point of view, but how can thermomechanical noise be translated to the actual resolution of the specific quantity the sensor is designed for (e.g. acceleration, force, fluid flow)? And how does thermomechanical noise lead to specifications for future electrical MEMS test equipment?
Biography Dennis Alveringh
Dr. Ir. Dennis Alveringh received the MSc degree in electrical engineering from the University of Twente, Enschede, The Netherlands, in 2013, on the subject of microfabricated multi-axis capacitive force/torque sensors. He joined the Integrated Devices and Systems Group, MESA+ Institute for Nanotechnology at the same university where he finished his PhD research on physical microfluidic sensors, e.g., noise limitations in Coriolis mass flow sensors, density sensors, relative permittivity sensors, and pressure/flow sensor integration for viscosity sensing. In 2018, he joined Salland Engineering (Europe) B.V. where he focuses on test development for ICs and MEMS.
PZT Microcantilever Sensors - Aleksandar Andreski - Saxion/Tech4Future
Abstract: Readout Strategies for PZT Microcantilevers in E-Nose Applications
Electronic detection of volatile organic compounds (VOCs) in gaseous media has many applications in the environmental , medical  and security  sectors. One of them is the early detection of various pollutants, of fire/burning, defects in equipment and even diseases. Such quick detection enables preventive actions to be taken as soon as possible. In early detection applications, the sensors must however
be able to detect very low VOC concentrations, typically in the 10s of ppm to 100s of ppb range. The technological challenge is then to achieve as low detection limit (LOD) as possible while still preserving selectivity to the desired panel of VOCs. The basis for our work lies in learning more about the practical applicability of piezo-MEMS technology, in this case for early detection of VOCs. Drifts in the underlying physical and chemical processes as well as environmental variations introduce uncertainties that can partly be reduced by suitable readout techniques. So, for example, the electronic interface to a vibrating piezoelectric cantilever sensor can be designed so as to minimize the influence of the parallel parasitic capacitance of the piezo-layer, thus preventing any drifts therein to result in false readings. On the other hand, fast incremental measurements (with e.g. a switched sample-flush procedure) will naturally reject all drifts that appear on time-scales larger than the measurement speed. Such methods are however not always practical for a given application, leading to compromises and an LOD which may be different that figures reported in the research literature.
Here we present various readout strategies optimized for achieving low detection limits for piezo-actuated MEMS cantilevers. The two most commonly used types of readout are impedance-based methods and phase-lock methods. We compared them with regard to speed, ease of implementation in an end-product and practically achievable detection limit. Our results are supported by measurements on PZTactuated
Biography Aleksandar Andreski
Aleksandar Andreski is born in 1978 in Ohrid, Macedonia. He graduated in
Electronics a Telecommunications at the SS Cyrul a Methodius University in Skopje, Macedonia (2001) en then studied Microelectronic Design at the TU Delft where he graduated in 2003. After that, he worked for Philips
Semiconductors (now NXP) in the Chief Technology Office as an IC design engineer until 2006 when he left for the University of Twente. He has received his PhD on the topic of high-speed superconducting electronics from the University of Twente in 2011. Since then he works at the Saxion University of Applied Sciences as a lecturer/researcher, then head lecturer and now as an associate lector on the topic of Reliability of chip-based MEMS/NEMS devices.
Low capacitance - Armando Bonilla Fernandez - Salland Engineering
Abstract: PoC - integrating low capacitance measurement into ATE
The use of MEMS devices is continuously growing. Nowadays, one of their biggest applications is in the sensing field, where MEMS are used to develop pressure sensors, accelerometers, gyroscopes, inertial combos, etc. For such sensors, a capacitive read-out is preferred in many cases due to its advantages, which include low temperature coefficients, low power dissipation, low noise and low-cost fabrication. One of the main challenges of MEMS devices’ fabrication is the fact that high-volume testing normally requires custom-made test set-ups. This is due to the complexity of multi-domain systems. In this session, we will discuss a proof-of-concept to check the feasibility of integrating a low capacitance measurement into an Automatic Testing Equipment (ATE). For this proof, special attention has been paid to the distance between both the paired Device Under Test & Measurement system and the multichannel instrument implementation. Based on this proof-of-concept, our aim is to optimize the testing procedure for a wide range of MEMS devices.
Biography Armando Bonilla Fernandez
Armando has a Bachelor degree in Mechatronics from the UANL in Mexico with 3 years of experience in industrial automation. He received the MSc degree in electrical engineering from the University of Twente, Enschede, The Netherlands, in 2016, with specialization in Robotics and Mechatronics. In 2017 he joined Salland Engineering (Europe) B.V. where he focuses on Design Verification of electronic instrumentation and hardware design.