Kristofer S.J. Pister (Advisor)

Research Advised by Professor Kristofer S.J. Pister

Pister Group:  List of Projects | List of Researchers

Toward Highly Digital Neural Recording ADCs

Yu-Chi Lin
2026
Spring 2026 BSAC Research Review Presentation View Presentation View Slides Project:...

A System Supporting Tiny Networked Sensors

Jason Hill
David Culler
Kristofer S.J. Pister
2000

As the post-PC era emerges, several new niches of computer system design are taking shape with characteristics that are quite different from traditional desktop and server regimes. One of the most interesting of these new design regimes is networked sensors. The networked sensor is enabled, in part, by "Moore's Law" pushing computing and storage into a smaller, cheaper, lower-power unit. However, three other trends are equally important: complete systems on a chip, integrated low-power communication, and integrated low-power devices that interact with the physical world. The combination of...

Micromachined Resonators

Dubravka Bilić
Roger T. Howe
Kristofer S.J. Pister
Roberto Horowitz
2001

In this work, we present approaches of making a micromachined resonators and oscillators. In the first study, we investigated the effects of anchoring on the resonator's performance. Using the Analog Devices BiMEMS integrated technology, double-ended tuning fork resonators have been fabricated with on-chip circuitry. The results show an improvement in the resonator's quality factor when using anchors with multiple contacts to the substrate. Resonators with frequencies up to 3MHz were tested at µTorr pressures to give quality factors as high as 58,000.

In order to reduce...

Miniature-Scale and Micro-Scale Rotary Internal Combustion Engines for Portable Power Systems

Kelvin Fu
A. Carlos Fernandez-Pello
Albert P. Pisano
Kristofer S.J. Pister
Dorian Liepmann
2001

This work describes the development of both miniature-scale and micro-scale rotary internal combustion engines. This work is part of a project to develop a portable, high specific energy, liquid hydrocarbon-fueled power supply. A Wankel-type rotary engine was chosen for development because of its self-valving operation, planar geometry, and the ability to extract either mechanical or electrical power. To investigate engine behavior and design issues, larger-scale "mini-rotary'' engines have been fabricated from 4 steel. Mini-rotary engine chambers are approximately 1000 mm3 to 1 700 mm3 in...

CMOS Imaging Receivers for Free-Space Optical Communication

Brian Leibowitz
Kristofer S.J. Pister
Bernhard E. Boser
Andrew Packard
2004
Free-space optical communication is an attractive alternative to radio communication for low power, long-range communication between small devices, primarily because utilization of shorter radiation wavelengths allows for more directional transceivers. At the transmitter, increased directionality allows for reduced transmission power because a given receiver will collect a larger fraction of the radiated energy. At the receiver, increased directionality allows for greater...

Hydrogel Actuated Carbon Fiber Microelectrode Array

Oliver Chen
Michel M. Maharbiz
Kristofer S.J. Pister
2023

Glial passivation and subsequent electrical insulation of implantable microelectrodes is a major bottleneck for long-term viability of neural probes. Self-deploying microelectrodes have been developed to minimize glial scarring and adverse biological effects near neural recording sites, but typically suffer from low electrode densities and deployment distance.

In this dissertation, we propose and evaluate a large displacement, self-deploying architecture using a water absorbing hydrogel to extrude a high density carbon fiber array out of a microfabricated shuttle. To enable mm-scale...

Rotary Inchworm Motor for Underwater Microrobot Propulsion

Mauricio J. Bustamante
Michel M. Maharbiz
Kristofer S.J. Pister
2024

Swimming microrobots have significant potential for biomedical applications and distributed sensing. To date, most work has relied on external fields for control control. To achieve au- tonomy, locally controllable propulsion mechanisms must be developed. This thesis presents an rotary inchworm motor designed to drive an artificial flagellum, inspired by bacterial flagellar motors found in nature. The design adapts electrostatic gap closing actuators with angled arms for rotational motion. The devices are fabricated in an SOI process with a bonded lid featuring through-wafer vias as a...

Algorithms for Distributed Sensor Networks

James D. McLurkin
Kristofer S.J. Pister
1999

A distributed sensor network is many (100-10000) autonomous sensor nodes spread out over a large area. Each node is equipped with a processor, mission-specific sensors, and short-range communications. Local interactions between sensor nodes allow them to reach global conclusions from their data. This work develops algorithms that allow:

The group to establish robust spatial patterns of messages The group to develop a communications network by dividing tasks among themselves Each mote to determine its position in physical space based on their location in the network topology Each mote...

Interceptor Swarms for Naval Defense: A Simulation-Based Evaluation of Hierarchical Swarm-vs.-Swarm Strategies

Titan Yuan
Daniel Lovell
Kristofer S.J. Pister
2026

Contemporary counter-unmanned aircraft systems (C-UAS) defense systems have become increasingly inadequate against coordinated swarm attacks, as evidenced by recent conflicts in Ukraine, in the Middle East, and over the Red Sea. The growing disparity between low-cost threat platforms and expensive interceptors, such as the \$2 million SM-2 missiles currently being deployed against Iranian Shahed-136 drones, creates an economically unsustainable defense posture, particularly for naval assets. We propose using hierarchical interceptors, where standard low-cost rockets are repurposed to carry...

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.