David A. Horsley (Advisor)

Research Advised by Professor David A. Horsley

BPN812: Improving Micro-Oscillators Performance By Exploiting Nonlinearity

Martial Defoort
2016

Due to their small size, micro-sensors experience complex phenomena including the emergence of nonlinearities, affecting the intrinsic properties of the system and commonly known to reduce its performance. In the case of micro-resonators, while larger displacement typically leads to lower SNR, it also increases the nonlinearity of the system, altering both frequencies and quality factors which in turn decrease stability and thus performance. However, a careful control of these nonlinearities opens the way for new implementation schemes and improved stability in micro-sensors, such as...

BPN599: MEMS Electronic Compass: Three-Axis Magnetometer

Soner Sonmezoglu
2017

High sensitivity, low cost, low power, and direct integration with MEMS inertial sensors, such as accelerometers and gyroscopes, make the MEMS magnetic sensor a very attractive option in consumer electronic devices. The goal of this project is to develop a low-power three axis MEMS magnetic sensor suitable for use as an electronic compass in smart phones and portable electronics. Our objective is to achieve a resolution of 100 nT/rt-Hz and power consumption of 0.1 mW/axis with DC power supply of 1.8 V. Although past devices designed by our group have demonstrated that our resolution...

BPN603: Micro Rate-Integrating Gyroscope

Parsa Taheri-Tehrani
2017

The goal of this project is to realize a micro rate-integrating gyroscope that produces an output signal proportional to rotation angle rather than rotation rate. This device would eliminate the need of integrating the gyroscope's rate output to obtain the angle. Gyroscope resonators have at least two resonant modes that can be coupled by Coriolis force. Difference in damping coefficients and stiffness of the resonant modes of the MEMS resonator known as anisodamping and anisoelasticity are main sources of error in RIG. So realizing a micro rate-integrating gyroscope can be achieved...

BPN817: Ultra-Low Power AlN MEMS-CMOS Microphones and Accelerometers

Yuri Kusano
2017

State-of-the-art (SOA) physical sensors used to monitor changes in the environment require active electronics that continuously consume power (in the order of mW) limiting the sensor lifetime to months or less. This project targets the integration of low frequency sensors with wake-up electronics that operates below 10nW (50dB lower than the SOA) and achieve high probability of detection (POD) (>95%) and low false alarm rate (FAR) (<1h^-1). To improve the sensor performance at low frequencies we design piezoelectric AlN MEMS microphones and accelerometers with high voltage...

BPN880: Synchronization in Micromachined Resonators

2018

Synchronization is a well-known phenomenon in nonlinear dynamics that is used to lock the frequencies of two oscillators for frequency stabilization applications. The simplest evidence of such frequency entrainment occurs between a self-sustained oscillator and an external tone2, when the latter is swept around the resonance frequency of the oscillator. Synchronization between two oscillators with frequencies related by an integer ratio can occur but requires coupling between the two modes. We present an experimental study of synchronization between two resonance modes of a single...

BPN785: Scandium AlN (ScAlN) for MEMS

Qi Wang
2018

The goal of this project is to design, fabricate and characterize novel MEMS devices based on scandium aluminum nitride (ScAlN) thin films. ScAlN thin film is a promising piezoelectric material due to its CMOS process compatibility, low relative permittivity and high piezoelectric coefficient and enables better performance of piezoelectric MEMS devices.

Project end date: 08/07/18

BPN628: Novel Ultrasonic Fingerprint Sensor Based on High-Frequency Piezoelectric Micromachined Ultrasonic Transducers (PMUTs)

Xiaoyue (Joy) Jiang
Qi Wang
2018

This project presents the first MEMS ultrasonic fingerprint sensor with the capability to image epidermis and dermis layer fingerprints. The sensor is based on a piezoelectric micromachined ultrasonic transducer (PMUT) array that is bonded at wafer- level to complementary metal oxide semiconductor (CMOS) signal processing electronics to produce a pulse-echo ultrasonic imager on a chip. To meet the 500 DPI standard for consumer fingerprint sensors, the PMUT pitch was reduced by approximately a factor of two relative to an earlier design. We conducted a systematic design study of the...

BPN849: Large-Amplitude Air-Coupled PMUTs

Yuri Kusano
2019

Ultrasonic transducers are widely used in various applications including medical imaging, nondestructive evaluation, object/gesture recognition, automotive, and range-finding. Compared to conventional capacitive micromachined ultrasonic transducers (CMUTs), piezoelectric micromachined ultrasonic transducers (PMUTs) have an advantage that they can be utilized without high bias voltages, resulting in simpler electronic interfaces. This project targets air-coupled PMUTs with wide bandwidth to achieve high axial resolution in pulse-echo imaging, where air-coupled transducers typically...

BPN851: Piezoelectric Micromachined Ultrasonic Transducers with Corrugated Diaphragms Using Surface Micromachining

Guo-Lun Luo
2019

A key metric of micromachined ultrasonic transducer (MUT) performance is the volume velocity, which determines the transmitting output pressure. Here, we present a study to demonstrate corrugated-diaphragm piezoelectric MUTs (PMUTs) which have up to 3.2X higher volume velocity than conventional PMUTs of the same area. The PMUTs are manufactured by a surface-micromachining process forming a high fill-factor (80%) array, and corrugations can be added without any additional masks or process...

Piezoelectric Micromachined Ultrasonic Transducers for Fingerprint Sensing

Yipeng Lu
David A. Horsley
Nesrin Sarigul-Klijn
Tingrui Pan
2015
Fingerprint identification is the most prevalent biometric technology due to its uniqueness, universality and convenience. Over the past two decades, a variety of physical mechanisms have been exploited to capture an electronic image of a human fingerprint. Among these, capacitive fingerprint sensors are the ones most widely used in consumer electronics because they are fabricated using conventional complementary metal oxide semiconductor (CMOS)...