UC Santa Cruz

Bioelectronics is an interdisciplinary field of materials science, electrical engineering, and biotechnology for the application of diagnosis and therapies in the healthcare industry. Owing to dissimilarities between soft, and wet living biological tissues and rigid, dry electronic devices at the human-machine interface, the development of more compatible materials and devices is a daunting challenge. Iontronics is a subdiscipline field that uses ions and biomolecules as the signal carrier to transfer information with biological systems, enabling direct and precise manipulation of physiological processes. They have been reported to trigger cell polarization status in vitro, controlling epileptiform activity in brain slice models, affecting sensory function in vivo, suppressing pain sensation in awake animals, and even modulating plant physiology. The core of iontronic devices is ion conducting materials that allow ions and biomolecules to move, such as polymers and hydrogels. The ion conducting materials also have the benefits of alleviating the mechanical mismatch between biological tissues and devices due to the low Young’s modulus. However, they haven’t obtained enough attention, and systematic study is absent.This work showed representative examples of ion conducting materials, including biomaterials, single-crystal polymers, and nanotubes, and their ionic conductivity characterization using two major methods. Moreover, a systematic study on polyelectrolyte hydrogel is presented with a novel method. The delivery of a large biomolecule, acetylcholine, is demonstrated with the optimized polyelectrolyte hydrogel. Additionally, I explored the design, fabrication, and implementation of bioelectronic devices that can deliver anions and even multiple ions with a single device. These results contribute to the iontronics field by broadening the knowledge of ion conducting materials and inspiring new device design for more complicated biological processes.