Michel M. Maharbiz (Advisor)

Research Advised by Professor Michel M. Maharbiz

BPN484: Effects of Cell Contact in Differentiation of Adult Neural Progenitor Cells

Sisi Chen

Cell-to-cell contact plays an important but poorly understood role in stem cell differentiation. Many proteins, such as notch, hedgehog, cadherins, and gap junctions rely on cell contact for signal transduction. The goal of this project is to probe the effects of cell contact in the differentiation of adult neural progenitor cells by high efficiency micropatterning techniques for monitoring dynamic activity or for downstream expression profiling. The adaptation of a microfluidic platform for the delivery of chemical gradients will also enable us to probe the ability of cells to...

BPN664: Blocks in Cells' Clothing: Mechanical Design of Tissues

Daniel J. Cohen

One of the most enduring paradigms in tissue engineering (the growth of artificial organs, graft tissues, etc.) is that the materials we use should be made to look more like the environment that cells normally experience. By contrast, I am working on a new type of structure designed to appear, to a cell, to be another cell. By using microfabrication methods and kidney cells, I am producing a library of different shapes, all of which are identified as 'cell' by actual cells. While esoteric, the ability to appear as a cell would encourage a number of new approaches to tissue...

BPN636: Extremely Elastic Strain Gauges via Nanotube Percolation Poisson Capacitors

Daniel J. Cohen

There is a growing need for stretchable electronics and sensors, and so we have developed a best-in-class stretchable strain gauge designed to meet this challenge. Our device works by measuring capacitive changes in parallel networks of carbon nanotubes separated by an elastomer. The device supports strains up to 100% with less than 3% variability over 3000 cycles, and does so at a materials cost of under 50 cents/sensor. The sensitivity is 0.99, while the theoretical maximum for a stretchable gauge is 1. By contrast, metal-foil gauges (the current standard) can only sustain strains...

BPN520: Miniaturized, Implantable Power Generator

Travis L. Massey

This research presents an implantable, miniaturized power generating system, a biofuel cell, which scavenges power from living organisms. The system harvests carbohydrates such as sugars stored inside the organism and, via an enzyme catalyst, decomposes these carbohydrates to generate electrical power. Our initial target for these devices is as a power supply for cyborg beetles. Our group has previously developed cyborg beetles, live beetles driven by wireless neural stimulator mounted on the dorsal thorax (see BPN 451). The stimulators are currently powered by a conventional...

BPN519: Harvesting Energy from Evaporation

Vedavalli G. Krishnan
Amrit Kashyap

Mimicking the transport of water in plants, the goal of this project is to harvest energy from evaporation-driven flows. This will be achieved by the use of an efficient micro-hydro power generator that is driven by the creeping flow of evaporation and fabricating a synthetic leaf that mimics the transport and transpiration of water in plants.

Project end date: 07/30/13

BPN584: Design, Fabrication and Testing of a High Density, Large Area µECoG Array

Peter Ledochowitsch
Raphael Tiefenauer

Electrocorticography (ECoG) strives to bridge the gap between traditional electroencephalography (EEG) and microneedle array recordings. While requiring a craniectomy, ECoG does not damage cortical tissue and is thus less invasive than microneedles. ECoG can achieve significantly higher spatiotemporal resolution than EEG because ECoG-electrodes are placed much closer to the signal sources in the brain. Commercially available ECoG arrays feature a small number of channels (<64) and a large electrode pitch (> 4 mm). Such coarse arrays likely undersample the signals available on...

BPN690: Manipulating Cellular Behavior and Wound Healing via Local Electric Field Stimulation

Daniel J. Cohen

One of the first things that happens when you cut your skin is that a DC electric field arises at the wound site. This field, first discovered in the mid-1800s, is called 'the wound field', and has been shown to exist in a variety of forms in a variety of wounds. The salient point of the wound field is that there is reason to believe that we may be able to manipulate it to improve how our injuries heal in certain cases. In particular, we are considering assisting healing of injuries to skin, intestine, and bone using a device that can encompass the wound site, monitor particular...

BPN717: Proof of Concept: Self-Assembly of a Multi-Cellular Synthetic-Biological Hybrid

Tom J. Zajdel

This year-long proof of concept explores the interplay between bacterial communication circuits and the surface topology of the substrate they are on, to see if certain designed surface features can be made to trigger genetic development switches. Differentiation due to a diffusible chemical signal is central in the development of multicellular organisms. Success in replicating this strategy on a synthetic structure enables a spatially programmable consortium of bacterial cells. Our aims were to enable the self-assembly of multicellular microbial films on the surface of synthetic...

BPN726: Transparent Microelectrode Arrays for Hybrid Experiments in Neuroscience

Brian Pepin

Optogenetics techniques that have been developed over the previous decade allow cell-type specific optical stimulation of neurons in-vivo. However, it remains a challenge to perform simultaneous electrical recording while providing optical stimulation due to photoelectric artifact generated at the microelectrode recording sites. This project aims to address this challenge by developing bio- compatible microelectrode arrays with optically transparent recording sites. Current devices are optimized for performing electrocorticography (ECoG) experiments and use Indium-Tin Oxide (ITO, a...

BPN518: Synthetic Turing Patterns

Justin Hsia

Understanding symmetry breaking is at the heart of developmental biology, from the origins of polarity, cellular differentiations, and how the leopard got its spots, as well as crucial to the future engineering of complex cellular ensembles. Alan Turing proposed a simple mathematical model that explains how the reaction-diffusion mechanism can cause an initially uniform concentration in an ensemble of cells to spontaneously become non-uniform and form patterns (Turing patterns). To date, no true synthetic Turing patterns have been created using gene networks, so our goal is to design...