THERMORESPONSIVE TRANSIENT ELECTRONIC SYSTEMS AND MICROFLUIDIC DEVICES FOR BIOMEDICAL APPLICATIONS

Abstract

There has been a push to develop novel materials and devices that are well-suited for diverse biomedical applications. Examples of emerging technologies that exhibit promising potential to advance current healthcare systems include transient electronics and microfluidics. By leveraging novel fabrication techniques and device architecture, there are opportunities to expand the utility of those technologies in a way that is not previously possible. In this dissertation, efforts are devoted to developing thermally triggered transient systems and simple yet efficient microfluidic devices for applications such as retrieval-free medical implant and high-yielding radiotracer synthesis for positron emission tomography (PET), respectively. For thermally triggered transient system, I focus on a class of thermoresponsive polymer that exhibits lower critical solution temperature (LCST) behavior. Different from previous dissolvable transient systems, developed thermoresponsive transient devices including conductors, capacitors, antennas, and LED circuits can function stably in warm water but stop working and physically disintegrate upon a cooling stimulus. As a result, triggered transience can be realized as needed by controlling external temperature. For microfluidics-aided radiotracer synthesis, I develop two different microfluidic devices for synthesis of different radiotracers, [18F]fallypride and [68Ga]PSMA. By employing developed microfluidic chips, complete production of desired radiotracers is successfully achieved with sufficient amount of radioactivity for human PET imaging. In addition, on-chip synthesized [68Ga]PSMA meets all requirements for direct patient injection, which represents an exciting advance of applying microfluidics for routinely clinical use. In summary, thermoresonsive transient systems and microfluidic devices presented in this dissertation expand the scope and capability of established technologies, implying promising potential for next-generation biomedical applications.