Opportunities and challenges in miniaturized implantable systems for clinical monitoring and neural interfacing for the brain
Dr. Jiho Shin (MIT)
Miniaturized electronic/optical implants play an important role in modern clinical medicine for diagnosing various brain disorders, as well as in fundamental neuroscience research for analyzing complex brain functions via modulation/recording of neural circuit dynamics. The capabilities to integrate ultrathin semiconductor devices composed of silicon and/or III-Vs such as gallium nitride and gallium arsenide, with encapsulations of biocompatible/resorbable polymers and biofluid barriers, can yield implantable devices with microscale dimensions that can form chronically stable interface to the brain. Combinations of different types of electronic/optical/photonic devices enable monitoring of a wide variety of biophysical/chemical markers of diseases ranging from traumatic brain injury, hydrocephalus, ischemic stroke, and metabolic encephalopathy, to mental disorders such as depression and dementia. In genetically modified animal models, optoelectronic devices can optogenetically modulate and record neural firings from distinct neuronal populations during various computational or behavioral activities, allowing neuroscientists to dissect how interactions among large networks of neurons lead to behavioral output such as motor actions or complex cognitive functions.
In this talk, I will introduce designs, fabrication strategies, and in vivo demonstrations of several types of implantable monitoring systems that are formed entirely from bioresorbable materials that naturally resorb via hydrolysis at programmed rates upon immersion in biofluids, thereby eliminating the need for surgical extraction after clinical use. I will also discuss opportunities in developing hetero-integrated optoelectronic platforms that could enable multi-regional optogenetic manipulation and functional recording in behaving mouse brains.