Date of Award

Spring 5-2017

Embargo Period

5-24-2017

Degree Type

Dissertation (CMU Access Only)

Degree Name

Doctor of Philosophy (PhD)

Department

Mechanical Engineering

Advisor(s)

Philip R. LeDuc

Abstract

Living systems have developed intricate multi-functional methods of sensing and responding to their surroundings at the cellular level at low spatial and energetic costs. Exploiting or mimicking these functionalities would have tremendous implications in both wearable devices, where both weight and power requirements are limiting factors, and drug delivery, where timed, localized release can have tremendous impact on drug efficacy. These goals can be achieved by either altering existing structures, such as modifying genetics in organisms to respond to stimuli, or by building synthetic lipid vesicle systems to mimic cellular morphologies. To the end of altering existing biological frameworks, we have genetically modified strains of Escherichia coli to function as chemical sensors within flexible, biomimetic systems. This approach expands the functionalities of soft machines at low cost to spatial and power considerations, two limiting factors to the development of these devices. By utilizing existing biological architecture and implementing modified organisms in flexible devices, we can produce high-functioning, low-energy wearable bio-sensors. Alternatively, we have also worked to replicate the mechanical sensing capabilities of cellular systems from a bottom-up direction, building a liposome-based system designed to sense mechanical deformation due to external forces. This device could be used as a localized drug release mechanism capable of responding to cues from outside of the body, as well as the framework for an artificial mechanotransduction system. To test this, we have developed a gut-on-a-chip framework in which to apply the magnetoliposomes for controlled rupture and localized drug delivery.

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