Liwei Lin (Advisor)

Research Advised by Professor Liwei Lin

Lin Group:  List of Projects | List of Researchers

Alexander Alvara

Graduate Student Researcher
Mechanical Engineering
Electrical Engineering and Computer Sciences
Professor Liwei Lin (Advisor)
Professor Kristofer S.J. Pister (Advisor)
Ph.D. 2025 (Anticipated)

Alexander Alvara is a final year Ph.D. Candidate in mechanical engineering who earned his 3 BS degrees from UC Irvine '17 concurrently in mechanical engineering, aerospace engineering, and materials science and engineering. Alexander is interested in extreme conditions applications and performance of MEMS devices as well as nanoscale materials engineering that investigates the interplay of materials with electromagnetism and light.

BPNX1061: Imaging Using PMUTs (New Project)

Nikita Lukhanin
Divij Muthu
Mostafa Sedky
Megan Teng
Tofic Esses
Linda Liu
Suraj Chamakura
Ryan Johnson
Chun-Ming Chen
2026

We use PMUTs for imaging.

Project is currently funded by: Member Fees

BPNX1036: Enhanced Gas Sensing with Machine Learning

Yuan Gao
Wei Yue
2026

Accurate and real-time gas detection is crucial for applications ranging from environmental monitoring to industrial processes. Traditional methods are often limited by low accuracy, slow response times, and high costs. This project introduces a scalable machine learning fusion system that integrates sensor fusion techniques to enhance detection performance. With encoder-decoder architectures and a decision fusion model, our approach significantly improves the accuracy of carbon dioxide sensing, achieving a mean absolute percentage error (MAPE) of 2.97% while reducing response and recovery...

Roll-to-Roll Soft Hydrogel Li-ion Battery

Jong Ha Park
2025
Fall 2025 BSAC Research Review Presentation View Presentation View Slides Project:...

High-SPL and Low-Driving-Voltage pMUTs by Sputtered Potassium Sodium Niobate

Fan Xia
Yande Xia
Sedat Pala
Ryuichi Arakawa
Wei Yue
Pei-Chi Tsao
Chun-Ming Chen
Hanxiao Liu
Megan Teng
Jong Ha Park
Liwei Lin
2023

This work presents an air-coupled piezoelectric micromachined ultrasonic transducer (pMUT) with
high transmitting acoustic pressure by using sputtered potassium sodium niobate (K,Na)NbO3
(KNN) thin film with a high piezoelectric coefficient (e31 ~ 8-10 C/m2) and low dielectric constant
(er ~ 260-300) for the first time. The fabricated KNN pMUT with a resonant frequency at 104.5 kHz
has been tested to exhibit unprecedented results: (1) high sound pressure level (SPL) of 109 dB/V
at a distance of 10 cm, which is 8 times higher than that of AlN-based pMUTs at a similar
...

BPN993: Roll-to-Roll Fabrication of Flexible Batteries

Jong Ha Park
Benjamin Toppel
Peisheng He
2026

Safe and deformable soft batteries are highly desirable for applications such as mobile electronics and conformable systems on irregular surfaces. Conventional Li-ion batteries rely on rigid packaging and hermetic sealing to block moisture intrusion and prevent leakage of toxic, flammable organic electrolytes. In contrast, recently reported deformable or stretchable batteries provide good conformability but suffer rapid performance degradation in ambient conditions, limiting their operating lifetimes. The fundamental challenge is that mechanical softness and gas impermeability are mutually...

BPN743: Highly Responsive pMUTs

Megan Teng
Peggy Tsao
Hanxiao Liu
Yande Peng
2026

Ultrasonics has been realized as a nondestructive measurement method for a variety of
applications, such as medical imaging, healthcare monitoring, structural testing, range finding, and motion sensing. Furthermore, high intensity ultrasound can be used in therapeutic treatments, such as lithotripsy for kidney stone comminution, hyperthermia for cancer therapy, high-intensity focused ultrasound (HIFU) for laparoscopic surgery and transcranial sonothrombolysis for brain stroke treatment. MEMS ultrasonic transducers are known to have several pronounced advantages over the conventional...

Peggy Tsao

Graduate Student Researcher
Mechanical Engineering
Professor Liwei Lin (Advisor)
Ph.D. 2027 (Anticipated)

Peggy Tsao received a B.S. in Mechanical Engineering from National Taiwan University in 2020. She is currently pursuing a Ph.D., major in Design and minor in MEMS/Nano in Mechanical Engineering at UC Berkeley under the supervision of Prof. Liwei Lin and is expected to graduate in 2027.

BPNX1070: Enhancing PMUT Outputs by Package Optimizations (New Project)

Mostafa Sedky
Nikita Lukhanin
2026

This work presents an evolutionary design framework for the horn package design of piezoelectric micromachined ultrasonic transducers (PMUTs). Our framework integrates high fidelity acoustic simulations, formulations for arbitrary three-dimensional horn geometries, and a custom genetic algorithm–based shape optimization strategy to customize and improve PMUT wave directivity and amplitude in health care and wearable devices applications.

Project is currently funded by: Industry Sponsored Research

Mostafa Sedky

Graduate Student Researcher
Mechanical Engineering
Professor Liwei Lin (Advisor)
Ph.D. 2028 (Anticipated)

Mostafa Sedky is a Ph.D. candidate in Mechanical Engineering at the University of California, Berkeley. His research focuses on simulation-driven design, optimization, and prototyping of advanced sensors and microactuators, combining scientific computing with novel engineering architectures to enhance acoustic performance of augmented reality devices. He has worked on microfluidic device prototyping as a Research Assistant at the American University in Cairo, vacuum chamber design for atomic layer deposition as an intern at Oxford Instruments, and thin-film optical manufacturing as a...