Michel M. Maharbiz (Advisor)

The signaling environment experienced by a single cell is highly dependent on its interactions with its neighbors, which may secrete locally acting factors or act via membrane bound receptor-ligand systems. Stem cells are particularly sensitive to these signals, which act in concert to regulate self-renewal and discrete transitions into distinct fates. In the case of the adult neural stem cell, decades of in vivo and in vitro work have illustrated specific roles for different types of niche cells and some of the molecular mediators...

Much of the world consists of many small things, animate or inanimate, interacting with each other to produce something larger than, and different from themselves. Comprising murders of crows, armies of ants, schools of fish, dunes of sand, and various organs in your body, the collective behaviors of these systems embody a different approach to engineering than we currently employ. This thesis explores three examples where principles from collective behaviors are deployed as engineering tools. The first example presents how the collective phenomenon of ‘percolation’ can be leveraged...

Over the past decade, there has been rapidly growing interest in wearable and implantable devices for a wide range of biomedical applications. For many applications involving prolonged contact with the body, devices that are compliant and can comfortably conform to and move with the patient are highly preferred. These flexible substrates (i.e. clothing, bandages, meshes, catheters, etc) can be instrumented to measure various physiological markers, such as temperature, pH, and oxygenation levels, to better inform clinical care. In this dissertation, I will discuss two examples of...

There is a growing need for technology that can control microscale oxygen gradients onto a tissue or culture sample in vitro. This dissertation introduces the oxygen microgradient chip (OMA), which employs electrolysis to generate oxygen microgradients within cell culture without forming bubbles. Dissolved oxygen generated at noble microelectrodes patterned on a chip surface diffuses through a gas-permeable silicone membrane and is dosed into cell culture. The amount of generated oxygen is directly proportional to a current flowing across the electrodes and thus can be controlled...