Kristofer S.J. Pister (Advisor)

Research Advised by Professor Kristofer S.J. Pister

BSAC's Best: Spring 2022 Oral Presentation Winners Announced

April 11, 2022

BSAC would like to thank all of the researchers who presented their research during BSAC's Spring 2022 Research Review, April 6 & 7.

BSAC Industrial Members voted for their favorite oral presentations and the results are in. Please join us in congratulating the winners of the Spring 2022 Best of BSAC honors, Nathan Lambert and Xintian Liu!

Watch the Spring 2022 Oral Presentations

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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...

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...

BPN915: Control of Microrobots with Reinforcement Learning

Nathan Lambert
2022

Generating low-level robot controllers often requires manual parameters tuning and significant system knowledge, which can result in long design times for highly specialized controllers. Moreover, with micro-robots the dynamics change on each design iteration and there is little experimental time to tune controllers. To address the problem of rapidly generating low-level controllers without domain knowledge, we propose using model-based reinforcement learning (MBRL) trained on few minutes of automatically generated data. Initial results showed the capabilities of MBRL on a Crazyflie...

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...

BPN803: Single Chip Mote

Alex Moreno
Joshua Alexander
Austin Patel
Anju Toor
Lydia Lee
2022

The single chip micro mote 3C (SCµM-3C) was designed to be a wireless sensor node on a chip capable of joining a network as a bare die with a standards compliant BLE and 802.15.4 mesh communication radio while fully self-contained and functional with no external components. SCµM-3C’s deep level of integration allows users to connect a battery, program using the touchless optical programmer and be ready to connect to the network. Advancements in communications as a crystal-free radio include SCµM-3C joining an 802.15.4 mesh network running OpenWSN, transmitting BLE beacon...

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...