Bridging Materials with the Mind: Novel Optical and Electronic Tools for Brain Research
The dichotomy between the materials world and the mental world has driven the curiosity of scientists to explore the wonders of the brain, as well as motivated the continued technological innovations based on materials science advances to understand the brain. A major challenge in understanding the brain is the spatiotemporal dilemma of neuroengineering: many important brain functions and cognitive processes occur in multiple regions and depths of the whole brain over months and years, but involve cellular electrophysiological changes that have to be quantified on the millisecond and micrometer scales of individual neurons. In this seminar, I will present two strategies to address this major challenge in neuroengineering: a new fluorescence-based in-vivo deep-brain imaging technique in the previously unexplored second near-infrared window (NIR-II window, 1,000-1,700 nm), and a new form of nanoelectronics that resembles the neural tissue and can be delivered in the brain by syringe injection like pharmaceuticals. Using bandgap-engineered nanomaterials and molecules, in-vivo NIR-II imaging allows visualization of sub-10 μm cerebral vessels in the mouse brain through intact scalp and skull and quantification of fast cerebral hemodynamics for stroke detection. Using tissue-like mesh electronics, stable long-term in-vivo brain and retina mapping at the single-neuron level has been achieved by blurring the distinction between biological and electronic systems. Both efforts have laid the foundation of ongoing research in our lab at the interface of materials science and brain science.