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

BPNX1024: Reusable Sweat Rate Sensor (New Project)

Seung-Rok Kim
Noelle Davis
2024

Sweat rate can provide the precautious signal of hyperhidrosis, hypohidrosis, and autonomic dysfunction. Currently, microfluidic and hygrometer-based sweat rate sensors are two types of available real-time sweat rate sensors. However, microfluidic device has issues of low temporal resolution, limited volume capacity, and surrounding artifact dependencies, while hygrometer-based devices also has overfilling and environmental artifact issues. In this work, we present reusable sweat rate sensor for continuous monitoring of sweat rate with novel sensor design.

Project...

BPNX1022: Gas Profiling for Human Health (New Project)

Carla Bassil
2024

It is well established that human skin constantly emits odors which vary with health or environmental conditions. In fact, canines have been trained to detect the changes in skin volatile organic compounds (VOCs) of epileptic and cancer patients. While a powerful tool for health monitoring, skin gas detection remains a largely untouched area due to the hundreds of different gases present at once. With recent advances in machine learning, ‘training’ an array of gas sensors to output a wholistic ‘gas fingerprint’ becomes a possibility. Challenges remain in sensor functionalization to...

BPNX1013: 3D Printing of Architected Hydrophones with Designed Beam Patterns (New Project)

Victor Couedel
2024

Piezoelectric hydrophones are crucial for underwater applications such as communication and seafloor mapping. Limited by the brittleness of piezoelectric ceramics, conventional manufacturing methods restrict hydrophones’ shapes to simple geometries such as disks, cylinders, or spheres, which limits the sensitivity, directivity pattern, and working frequency bandwidth of the device.


We are developping a new class of high-performance 3D printed piezoelectric hydrophones consisting of rationally designed micro-architectures. Using a high-
...

BPNX1017: 3D Printing of Functional Materials (New Project)

Zhen Wang
2024

3D printing enables the fabrication of 3D functional materials with complex structures associated to various functionalities. Developing 3D printing resins with different properties promises to fabricate a myriad of complex functional devices with e.g., self-sensing, actuation, and structural elements assembled in a designed 3D layout. In this project, we explore the achievable property space and the material-performance correlation of 3D printing by designing a series of photo-curable resins. We unveil how the functional groups of the resins synergistically impact the...

BPNX1019: 3D Printing of Piezoelectric Materials and their US Transducers & Sensor Applications (New Project)

Haotian Lu
2024

The performance of ultrasonic transducers is largely determined by the piezoelectric properties and geometries of their active elements. Due to the brittle nature of piezoceramics, existing processing tools for piezoelectric elements only achieve simple geometries, including flat disks, cylinders, cubes and rings. While advances in additive manufacturing give rise to free-form fabrication of piezoceramics, the resultant transducers suffer from high porosity, weak piezoelectric responses, and limited geometrical flexibility. We introduce optimized piezoceramic printing and...

BPNX1007: Surface Tension-Driven Liquid Metal Actuator

Peisheng He
Zihan Wang
2024

Surface tension plays an important role in miniaturized systems as the scaling law favors its relative significance over other forces such as gravity, magnetic, and structural stiffness. As such, surface tension effects have induced process issues in microfabrication such as stiction but also provided opportunities in using the surface tension to drive microdevices, such as those based on electrowetting-on-dielectric (EWOD), electrocapillary, and continuous electrowetting (CEW) mechanism, … etc. In this project, we exploit the giant outputs by the switching of surface tension...

BPNX1008: Dual-Path Noise Elimination (DuNE): A Noise-Cancellation Technique for Aptamer-Based Electrochemical Sensors

Wei Foo
2024

We have previously demonstrated electrochemical circuits for measuring the concentration of various biomolecules and drugs using structure-switching aptamers. Structure-switching aptamers are single-stranded nucleic acids that can be sequenced to exhibit conformational changes when bound to specific biomolecules. By conjugating aptamers with a redox reporter, voltammetry or amperometry-based measurements can be applied and signals in the nano to pico-amp scale can be captured using transimpedance amplifiers (TIA). Because the signals of interest are very small, noise-cancellation...

Hyong Min Kim

Graduate Student Researcher
Electrical Engineering and Computer Sciences
Professor Ali Javey (Advisor)
Ph.D. 2028 (Anticipated)

Hyong is a Ph.D. student in the Electrical Engineering and Computer Sciences Department at University of California, Berkeley. He received his Bachelor's Degree in Electrical Engineering from the Univeristy of Pennsylvania in 2023. In his undergraduate research, Hyong studied quantum emission from strained 2D materials, ferroelectric field-emission transistors based on AlScN/2D material heterostructures, and scanning probe characterization of 1D-2D material interfaces. Hyong's current research at Berkeley is on fabricating next-generation Mid-Wave Infrared (MWIR) optoelectronic devices...

BPN999: Wearable Sweat Sensors with High-Throughput Fabrication

Noelle Davis
Yullim Lee
Nicole Qing
Seung-Rok Kim
2024

We have been developing sweat sensors to analyze physiological and metabolic health information, such as sweat rate, glucose levels, pH, and various electrolytes, from any surface on the body surface where sweat glands are present. However, the stiff sweat sensors developed so far struggle to detect subtle signal changes, especially on soft skin. This is due to a mechanical mismatch between the rigid sweat sensor and the pliable skin, which can lead to motion artifacts and delamination of the patch from skin. Specifically, the stiff sensor cannot easily stretch along with the...

BPN997: Interface Piezoelectricity in Silicon

Haoxin Zhou
Kadircan Godeneli
Zihuai Zhang
Mutasem Odeh
Shahin Jahanbani
2024

Piezoelectricity is the ability of certain materials to generate an electric polarization in response to applied mechanical stress or generate a mechanical deformation in response to applied voltage. It has broad applications where transduction between electrical and mechanical energy is required. It may also play a negative role and affect the performance of electronic devices. An example is the piezoelectric loss in superconducting qubits.


While bulk piezoelectricity usually only exists in materials without inversion symmetry, lattice termination at the material surface, or...