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

BPN879: A Wearable Impedance-Based Microfluidic Sensor for Sweat Rate Monitoring

Li-Chia Tai
2017

A flexible and wearable sensor is presented for real-time monitoring of localized perspiration rate of human subjects. These sweat rate measurements are validated through controlled syringe pumping and a commercial sweat collector. Real-time on-body perspiration rate evaluation of human subjects is performed through cycling experiments to examine the change in sweat rate with different power output. Since it has been shown that the concentrations of a large number of sweat biomarkers are strongly related to the variation of a subject's perspiration rate, this platform is anticipated...

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...

BPN872: Compact Voltage Sensor for Power Lines

Duy-Son Nguyen
2018

This project is designed to measure the line-to-line voltages of distribution and transmission power lines by using very compact and inexpensive sensors that operate at low voltages. On a two-wire power line, the measurement devices are mounted on only one of the lines. The devices can also be applied in open air power substations and in buildings where high voltage power lines (e.g., 12,400 AC Volts) are used.

Project end date: 01/30/18

BPN780: Impedance Spectroscopy to Monitor Fracture Healing

Monica C. Lin
2018

An estimated 15 million fracture injuries occur each year in the United States. Of these, 10% of fractures result in delayed or non-union, with this number rising to 46% when they occur in conjunction with vascular injury. Current methods of monitoring include taking X-rays and making clinical observations. However, radiographic techniques lag and physician examination of injury is fraught with subjectivity. No standardized methods exist to assess the extent of healing that has taken place in a fracture, revealing the need for a diagnostic device that can reliably detect non-union in...

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...

BPN886: 2D Carbides as a New Family of Gas Sensing Materials with Wide Working Temperature Range

Xining Zang
Niravkumar Joshi
2018

Some of the 2d and 2d-like carbide exhibit tunable band structure with relatively high conductivity, which provides sensing function for dopants such as gas molecules. 2d-like carbide also has limited phase change induced nanostructure aggregation. With up to 1000K thermal stability, such carbides will be a better fit than other oxide and nitride materials in higher temperature sensing. For certain gases that require combustion sensing, nanostructure 2d-like carbides will be much stable and reliable. 2d-like Molybdenum carbide is three times more sensitive than graphene in response...

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

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...

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...

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...