Kristofer S.J. Pister (Advisor)

Research Advised by Professor Kristofer S.J. Pister

Yichen Liu

Graduate Student Researcher
Electrical Engineering and Computer Sciences
Professor Kristofer S.J. Pister (Advisor)
Ph.D. 2027 (Anticipated)
First-year Ph.D. student in EECS at UC Berkeley Concentration in MEMS The current project on locomotion controller design on micro-walker through reinforcement learning

BSAC Spring 2023 Research Review Presenter

MBRL for Micro-Robot Control: Evolution of Gaits and Implementation on SCuM

Yichen Liu
2023
Spring 2023 BSAC Research Review Presentation View Slides View this Presentation at 36:40

 Project: BPN915 - Kristofer S.J. Pister Group

A CMOS Biosensor for Infectious Disease Detection

Turgut Sefket Aytür
Bernhard E. Boser
Kristofer S.J. Pister
Eva Harris
2007

The timely and accurate diagnosis of infectious diseases is indispensable for directing patient management and informing larger public health decisions. For the individual patient, delays in accurate diagnosis may delay necessary treatment and consequently result in a negative outcome. From the public health standpoint, prompt awareness of disease outbreaks is critical for an effective response. In developed countries, both the medical infrastructure and...

BPN948: Wireless Tactile Stimulation with MEMS Inchworm Motors

Dillon Acker-James
2022

The goal of this project is to make an untethered MEMS tactile stimulator. Electrostatic inchworm motors made in SOI substrates routinely generate 1-15 mN of force and 2 mm/s travel, making them a viable option for a millimeter-scale wireless tactile stimulator. Collaborating with Professor Eric Paulos and his students, our first step is to conduct haptic sensation surveys in order to understand what a user feels based on different forces. Our current chips provide a force range of 1mN up to 15mN, but we plan to increase this in the future. Our next step would be to integrate the MEMS...

Kris Pister Appointed Faculty Director to Marvell NanoLab

February 1, 2020

BSAC Co-Director Kris Pister has been named the new faculty director of the UC Berkeley Marvell Nanofabrication Laboratory (NanoLab) at CITRIS. The appointment, which became effective Jan. 1, brings in a veteran user known for his advances in microelectromechanical systems (MEMS) to head the cutting-edge facility.

Pister, who earned his master’s and Ph.D. in electrical engineering and computer sciences from UC Berkeley in 1989 and 1992, recalls the many hours spent in the Berkeley...

PCB-Less Integration of a Robust Wireless MEMS Tactile Package

Dillon Acker-James
Kristofer S.J. Pister
2023

Creating a wireless tactile actuator the size of an aspirin will allow for more precise physical stimulation. This will lead to a more immersive virtual reality (VR) experience and better convey information via touch. Making this wireless tactile actuator can be accomplished by further utilizing the existing Si on Insulator (SOI) structure. Currently, a printed circuit board (PCB) is used for the sole purpose of assembly, however, further utilization of the Micro Electromechanical Systems (MEMS) SOI structure can allow the chip to operate as both the actuator and housing package. In...

Dillon Acker-James

Graduate Student Researcher
Electrical Engineering and Computer Sciences
Professor Kristofer S.J. Pister (Advisor)
M.S. 2022

Currently pursuing a doctoral degree after getting a Bachelors degree in Electrical Engineering from UC Santa Barbara, where my coursework and research in the Mishra lab focused on fabrication and device physics. In graduate school I'm working on the building blocks for a platform that will be able to house various sensors and devices in a dirty envirnment, like in contact with the human skin, and even fully submerged in an aqueous medium.

After an internship with Apple and Iota Biosciences I am driven to make MEMS-powered medical devices, enhanced and controlled by on-...

Frequency Compensated Crystal-Free 802.15.4 Wireless Radio

Alex Moreno
Kristofer S.J. Pister
2022

Crystal-Free radios are susceptible to frequency drifts due to temperature and voltage. Compensation for the frequency drift in the 2.4 GHz local oscillator due to voltage variation was demonstrated for a Crystal-Free radio while powered from a solar cell under 200 mW/cm2 of irradiation and a 0805 capacitor. Without compensation the local oscillator frequency would vary by 2.4 MHz while the 802.15.4 packets were transmitted resulting in a loss of 100B of the payload. With frequency drift compensation that oscillator frequency varied less than 300KHz and the full length 125B 802.15.4...

Nonlinear Dynamics of Lateral Electrostatic Gap Closing Actuators for Applications in Inchworm Motors

Ahad M. Rauf
Daniel Contreras
Ryan Shih
Craig Schindler
Kristofer S.J. Pister
2022

We present a nonlinear dynamics model for lateral electrostatic gap closing actuators (GCAs) operated in air and underwater. We factor in finger bending and the release phase’s initial velocity over prior work, and we systematically study the effect on GCA pull-in and release time by varying both the finger length and the release spring constant. Simulation results are then compared to experimental data with good conformity. We also apply this dynamics model to optimize electrostatic inchworm motors for drive frequencies up to 40 kHz and speeds up to 415 mm/s, over 11× faster than what has...

Jumping Silicon Microrobots With Electrostatic Inchworm Motors and Energy Storing Substrate Springs

Craig Schindler
2020

Jumping microrobots are a burgeoning area of autonomous microelectromechanical systems (MEMS). This dissertation presents background, theory, designs, and results of the first jumping microrobots fabricated in a silicon-on-insulator (SOI) process using electrostatic inchworm motors etched into the device layer silicon and energy storing springs etched into the silicon substrate. Substrate silicon is much thicker than device layer silicon, and can therefore store a lot more mechanical energy per unit area than can device layer silicon. New high force density electrostatic inchworm motors...