Liwei Lin (Advisor)

Research Advised by Professor Liwei Lin

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...

BPN993: Safe and Deformable Soft Batteries

Peisheng He
Jongha Park
2024

Safe and deformable soft batteries are desirable for modern products that call for good safety features such as cell phones and good conformability to be embedded onto irregular surfaces in electronics systems. Current Li-ion batteries on the commercial market are rigidly packaged and hermetically sealed to prevent: 1) the intrusion of moistures which degrade performances; and 2) the leakage of toxic and flammable electrolytes due to mechanical damages. On the other hand, various deformable/stretchable batteries have been reported in research articles and they have shown good...

BPN955: Nanoplasmonic Biosensing

Kamyar Behrouzi
2024

Access to affordable and user-friendly biosensors is crucial for advancing global healthcare. While lateral flow immunoassays have been the primary solution for decades, their limited sensitivity and suboptimal sample utilization present challenges. This project represents a systematic progression towards developing economically viable biosensors with heightened sensitivity, covering a range of diseases from viral infections to cancer. By integrating nanoplasmonics to induce visually perceptible signals and harnessing the coffee ring effect for protein pre-concentration, we achieved...

BPN940: Self-Healing Materials for Sensing and Energy Harvesting Applications

Peisheng He
Zihan Wang
2024

Animal skins often possess both functions of sensing and actuating to detect external stimulations and change shapes when needed, respectively. Furthermore, many animals, such as jellyfish and leptocephalus (eel larvae) have tissues that are transparent and ultra-stretchable, which are difficult to build in synthetic sensors and actuators. Moreover, all these living skins have self-healing properties, i.e. to restore their critical functions after being damaged. On the contrary, artificial electronic systems are often brittle and non-transparent. As such, biomimetic, skin-like materials...

BPN743: Highly Responsive pMUTs

Peggy Tsao
Megan Teng
Hanxiao Liu
Yande Peng
2024

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.

Sujoy Kumar Ghosh

Postdoctoral Researcher
Mechanical Engineering
Professor Liwei Lin (Advisor)

BPN992: Sensing and Actuation Applications Using Lithium Niobate PMUTs

Wei Yue
Megan Teng
2024

Sensing, actuation and imaging applications based on ultrasounds could expand to many applications by means of miniaturization and low power consumption via MEMS fabrication technologies. Piezoelectric micromachined ultrasound transducers (PMUTs) with thin film designs have emerged as key commercial products but current state-of-art PMUTs are limited by the acoustic power/pressure for applications within a limited range by using AlN as the piezoelectrical material due to its process compatibility with microelectronics. One BSAC industrial member has developed a process to make PMUT...

Fan Xia

Graduate Student Researcher
Mechanical Engineering
Professor Liwei Lin (Advisor)
Ph.D. 2026 (Anticipated)

BPN941: Ultrasound-Induced Haptic Interface

Fan Xia
Wei Yue
2024

The next big thing, AR/VR, requires an immersive Human Machine Interface (HMI) in addition to visual and sound stimuli. Although skin is the biggest organ in the human body, very few efforts compared to visual and auditory senses have been done to develop a “sense of touch”. The mechanical stimulus to generate the touch sense by the embedded mechanoreceptors in the skin at different depths has been created in many ways as vibratory actuators, microneedles, etc. In this project, we are investigating to create haptic interface via radiation force generated by piezoelectric...