Physical Sensors & Devices

Research that includes:

  • Silicon MEMS actuators: comb, electro-thermal, and plastic deformation
  • Precision electronic sensing and measurements of capacitive, frequency, and coulombic MEMS variables
  • Structures and architectures for gyroscopes, accelerometers, micro strain gauges for direct application to rigid structures e.g., steel, and levitated MEMS

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...

BPN901: Roll-to-Roll Gravure Printed Electrode Arrays for Non-Invasive Sensing Applications

Mallika S. Bariya
2018

As recent developments in noninvasive biosensors spearhead the thrust towards personalized health and fitness monitoring, there is a need for high throughput, cost-effective fabrication of flexible sensing components. Towards this goal, we are working on roll-to-roll (R2R) gravure printed electrode arrays that are robust under a diverse range of electrochemical sensing applications, including detection of ions, metabolites, and heavy metals in human perspiration. R2R printed arrays that are suitable for continuous, in situ use are a key step towards enabling large-scale production of...

BPN898: A Wearable Microfluidic Sensing Patch for Dynamic Sweat Secretion Analysis

Hnin Y. Nyein
2018

Wearable sweat sensing is a rapidly rising research driven by its promising potential in health, fitness and diagnostic applications. Despite the growing field, major challenges in relation to sweat metrics remain to be addressed. These challenges include sweat rate monitoring for its complex relation with sweat compositions and sweat sampling for sweat dynamics studies. In this work, we present a flexible microfluidic sweat sensing patch that enhances real-time electrochemical sensing and sweat rate analysis via sweat sampling. The device contains a spiral-patterned microfluidic...

BPN891: Dopant-Free Asymmetric Heterocontact Silicon Solar Cells with >20% Efficiency

Wenbo Ji
2019

A salient characteristic of solar cells is their ability to subject photo-generated electrons and holes to pathways of asymmetrical conductivity—‘assisting’ them towards their respective contacts. All commercially available crystalline silicon (c-Si) solar cells achieve this by making use of doping in either near-surface regions or overlying silicon-based films. Despite being commonplace, this approach is hindered by several optoelectronic losses and technological limitations specific to doped silicon. A progressive approach to circumvent these issues involves the replacement of...

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...

BPN868: Self-Cleaning Mass Sensor for Particulate Matter Monitors

Zhiwei Wu
2019

When people inhale small particles, such as soot, they may develop pulmonary, cardiac and neural problems, and millions may die prematurely. Therefore, there is need for widely accessible particulate- matter monitors to enable individuals to avoid areas of high particulate concentration. We propose to test means conceived for cleaning the surfaces of the particle mass-measuring sensors after each particulate deposition, as well as recently...

BPN772: Graphene for Room Temperature Gas Sensors

Takeshi Hayasaka
Zhichun Shao
Vijay Kumar
Ritu Malik
2019

As air pollution from industrial and automobile emissions becomes more and more severe, a personalized, integrated, gas sensor is desirable for everyone to monitor everyday air quality, as well as their personal health condition noninvasively. Such sensors should have desirable features like energy efficiency, miniature size, accurate response (down to ppm level), and selectivity. Traditional bulk MOX-based gas sensors work in the temperature range of 300C to 400C,...

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...

BPN770: Chemical Sensitive Field Effect Transistor (CS-FET)

Niharika Gupta
2019

Silicon IC-based fabrication processing will be used to develop novel compact gas sensors that, unlike current sensors, will operate at room temperature, consume minimal power, exhibit superior sensitivity, provide chemical selectivity and multi-gas detection capabilities, and offer the prospect of very low-cost replication for broad-area deployment. We name this device structure “Chemical Sensitive FET” or “CS-FET.” The operation of the CS-FET involves transistor parametric differentiation under...

BPN923: Rapid Isolation and Identification of Drug-Resistant Pathogens with Smartphone-Based Optical System (SOS)

Wonseok Kim
Youngseop Lee
2020

The rapid isolation and identification of antimicrobial-resistant pathogens are critically demanded in global healthcare and precision medicine. However, time-consuming, culture-based methods are currently used for the detection of pathogens since there is no rapid precision molecular diagnostic platform. In this work, we develop a rapid isolation and identification of drug-resistant pathogens with smartphone-based optical system (SOS). For the pathogens detection from human blood sample, we precipitate RBCs with pre-mixed dextran for 10...