Flexible Nano-/Micro-Bioelectronics for Neural Interfaces

Abstract

Bioelectronics explores the use of electronic devices for applications in signal transduction at their interfaces with biological systems. Ultra-flexible nano- and micro-scale bioelectronic systems have enabled seamless integration at the interfaces between electronics and biological systems and will provide new scientific and technological opportunities. In particular, interfacing nanowires with biological systems has opened up studies at length scales that are difficult to access with conventional electrical monitoring and modulation techniques, due to the comparable dimensions of nanowires to biomolecules and biosystems. In addition, developing ultra-flexible electronics that matches the mechanical properties of biological tissues could minimize the immune response induced by the traditional rigid electrodes, and thus could serve as the basis for a seamless interface of electronics with biological systems. In this thesis, I focus on flexible nano- and micro-scale bioelectronics for neural interfaces. First, I review recent progress in nanowire-enabled monitoring of electrogenic cells, including cardiomyocytes and primary neurons, as well as interfacing in vitro and in vivo with synthetic and natural tissues. Second, I report a biomimetic approach that enables spontaneous internalization of nanowires into primary neuronal cells without compromising cellular integrity or viability. Third, I describe my work on nanowire transistor array enabled scalable intracellular recording. Fourth, I focus on studies showing how functionalization of the flexible mesh electronics with antibodies or aptamers capable of recognizing and targeting specific cell surface receptors can enable in vivo electrophysiology from different cell types and neuron subtypes for the first time. Finally, I introduce a novel neuroelectronic interface – an ultra-small and flexible endovascular neural probe that can be implanted into small 100-micron scale diameter blood vessels in deep brain regions without damaging adjacent neural tissue or vascular structures.