Kristofer S.J. Pister (Advisor)

Research Advised by Professor Kristofer S.J. Pister

Pister Group:  List of Projects | List of Researchers

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...

David Burnett

Alumni
Electrical Engineering and Computer Sciences
Professor Kristofer S.J. Pister (Advisor)
Ph.D. 2019

Oliver Chen

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

Oliver graduated with the B.S. degree in Electrical Engineering from the California Institute of Technology in 2016. He is currently working on hydrogel actuated carbon fiber microelectrode arrays in as an EECS PhD student at the University of California, Berkeley with Prof. Michel Maharbiz. He is a recipient of the NSF Graduate Research Fellowship.

Oliver is interested in biomedical device technology related to both systems-level design and MEMS devices. This includes microfabrication and implementation of implantable devices, in particular, neural probes for brain-machine...

Robust Crystal-Free Oscillators and the Invisible Keyboard

Alex Moreno
2022
Fall 2022 BSAC Research Review Presentation View Slides View Presentation at 17:08

BSAC's Best: Fall 2022 Awards Announced

September 28, 2022

BSAC would like to thank all of the researchers who presented their research during BSAC's Fall 2022 Research Review on September 21st.

BSAC Industrial Members voted for the outstanding paper and presentations and the results are in. Please join BSAC in congratulating the recipients of the Fall 2022 Best of BSAC honors, Alex Moreno, Mutasem Odeh, and Vivian Wang!

Outstanding Presenter...

BPN959: Self-Righting for Micro Robots

Alexander Alvara
2022

In developing micro-robots for exploration in non-uniform terrain, it is often the case that robots fall over. This work seeks to provide a solution in the self-righting of autonomous micro-robots to overturn a 1cc, 1 gram cube microrobot with regular octahedral symmetry that has fallen on either of its four sides and overturning said microrobot once upside down. Our design currently consists of a 3-bar linkage in conjunction with an electrostatic inchworm motor. First-generation devices are in fab as of August. Hand analysis indicates that self-righting from any face should be...

BPN857: Miniature Autonomous Rockets

Alexander Alvara
2022

Pico air vehicles (PAVs), sub-5cm aerial vehicles, are becoming more feasible due to advances in wireless mesh networks, millimeter-scale propulsion, battery technology, and MEMS control surfaces. Our goal is to develop an aerodynamic MEMS control surface that could be used in PAV applications. This device will use electrostatic inchworm motors (capable of outputting 15mN) to extend an airfoil through 10 degrees. Using information from previous work that demonstrated roll control, we expect to extend automated flight control to pitch and yaw. We predict and output torque of 2.3 uNm,...

BPN890: Hydrogel Actuated Carbon Fiber Microelectrode Array

Oliver Chen
2022

Glial scarring and passivization of long-term implanted neural probes is one bottleneck in brain- machine interface technology. However, ultraflexible probes with similar mechanical properties as tissue have been shown to minimize scarring and other biological responses. We propose a flexible, microscale neural probe that can be actuated using an expanding hydrogel. This device is designed to be able to record neural signals up to hundreds of microns away from the insertion site. This design can allow for high-density, accurate neural recordings for a wide variety of clinical applications...

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...