Kristofer S.J. Pister (Advisor)

Research Advised by Professor Kristofer S.J. Pister

Pister Group:  List of Projects | List of Researchers

BPN969: Joule Bonding: Localized Solder Bonding for Heterogenous Integration of MEMS

Daniel Teal
2022

We are developing a new MEMS bonding process in which we use extremely carefully controlled resistive heating to make a solder bond with negligible substrate temperature rise and tighter temperature control than in laser bonding; we do this by using the temperature change of the heater resistivity as a temperature sensor for closed-loop control. Previously, we analyzed transient heat flow and showed initial progress toward heater control. Now, we have completed our theoretical analysis with a description of temperature fluctuations due to local inhomogeneities on the chip and how to...

Single-Chip Micro Mote in EEG, fMRI, and TMS Systems

Joshua Alexander
Kristofer S.J. Pister
2022

The goal of this project is to measure EEG signals in an MRI during TMS and report the EEG measurements wirelessly. The opportunities combining SoC-based devices with cutting-edge technology are rapidly expanding. A Single Chip Micro-Mote (SCμM) that has been developed as an ultra-small crystal-free SoC opens up the door of possibilities even more. Similarly, brain stimulation and measurement has taken a leap forward as Transcranial Magnetic Stimulation (TMS), Electroencephelography (EEG), and functional Magnetic Resonance Imaging (fMRI) have grown in popularity. A structure that...

Synergy of Prediction and Control in Model-based Reinforcement Learning

Nathan Lambert
2022

Model-based reinforcement learning (MBRL) has often been touted for its potential to improve on the sample-efficiency, generalization, and safety of existing reinforcement learning algorithms. These model-based algorithms constrain the policy optimization during trial-and-error learning to include a structured representation of the environment dynamics. To date, the posited benefits have largely been left as directions for future work. This thesis attempts to illustrate the central mechanism in MBRL: how a learned dynamics model interacts with decision making. A better understanding of...

BPN930: Robust MEMS Inchworm Motors

Daniel Teal
Dillon Acker-James
Alex Moreno
Alexander Alvara
2022

We are developing robust, high force, low power, and efficient MEMS inchworm motors for microrobots. So far, we have created 3x4.7mm motors in a 40um SOI process capable of linearly actuating a shuttle with 15mN force and 5mm/s travel at < 1mW power draw to > 50mm displacement. By integrating these motors into 550um thick reinforcing silicon substrate structures we created a microgripper capable of reliably lifting 1g weights and other macroscopic objects. We also showed gripper operation off solar power in BSAC project BPN873. Finally, we have analyzed motor efficiency, an...

BPN958: Printed Miniaturized Li-Ion Batteries for Autonomous Microsystems

Anju Toor
2022

Despite the popularity and widespread demand for miniaturized electronic devices, limited advances have been made to design energy storage mechanisms that can satisfy their power and size requirements. We have developed a fabrication process to produce miniature Li-ion batteries by combining the stencil printing process to deposit thick high capacity electrodes and an adhesive based sealing method for battery packaging, with active areas as small as 1 mm2. The battery consists of printed anode and cathode layers based on graphite and lithium cobalt oxide (LCO) respectively. These...

BPN826: Autonomous Flying Microrobots

Nathan Lambert
2022

Among the state of the art academic research on pico air vehicles, the majority has focused on biomimetic flight mechanisms (e.g. flapping wings). This project looks to develop new microfabricated transduction mechanisms and systems for flying microrobots with the goal of opening up the application space beyond that allowed by the industry-standard single quadcoptor. One proposed mechanism, electrohydrodynamic (EHD) force generated via sub-millimeter corona discharge, functions silently and with no moving parts, directly converting ion current to induced airflow. Current work is...

Joshua Alexander

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

Anju Toor

Alumni
Electrical Engineering and Computer Sciences
Professor Kristofer S.J. Pister (Advisor)
PostDoc 2022

Anju completed her Ph.D. in Mechanical Engineering at the University of California, Berkeley in 2017 under the guidance of Prof. Albert Pisano. She also collaborated closely with Prof. Thomas Russell and Brett Helms at LBNL.

With Ana Arias and Kristofer Pister as her advisors, Anju is working on printed, miniaturized Li-ion batteries.

Howard Zhang

Alumni
Electrical Engineering and Computer Sciences
Professor Kristofer S.J. Pister (Advisor)
M.A. 2021

Howard completed undergraduate at UC Berkeley studying Electrical Engineering and Computer Sciences. Now, he is pursuing a M.S degree in EECS, doing research in machine learning and robotics.

Emmanuel Sin

Alumni
Electrical Engineering and Computer Sciences
Professor Kristofer S.J. Pister (Advisor)
Ph.D. 2021