SYRINGE-INJECTABLE NANOELECTRONIC INTERFACES TO SOFT-MATTER TISSUES

Speaker: Thomas Schumann

Abstract: Tightly integrating solid-state electronic devices with biological systems is an important problem for medicine and fundamental neuroscience. The e cacy of deep brain stimulation (DBS) and in vivo brain recording studies with multielectrode arrays (MEAs) both depend on the ability of the devices to achieve e cient electrical coupling with the target tissues. However, mechanical mismatch of solid-state electronics with soft-matter tissues, and the accompanying chronic immune response, is a key barrier to long-term clinical success and achieving high-quality recordings throughout longitudinal neuroscience studies. Here, I discuss how nanoscale physics can be harnessed to surmount this challenge both mechanically and electrically. First, I introduce mesh electronics: macroporous networks of sensing electronics exible enough to be injected into brain tissue via syringe. With a bending sti ness of approximately 0.1 nN-m, mesh electronics have a mechanical softness comparable to a 150-μm-thick slice of brain tissue, allowing for seamless integration with neurons and chronic neuroscience studies on at least a year timescale. Next, I discuss how silicon nanowire  field-effect transistors (Si NW-FETs) have preferential scaling laws compared to conventional recording electrodes and can be incorporated into mesh electronics with a revised microfabrication method and \plug-and-play" interfacing design. Injection in vivo demonstrates the unique spectroscopic features of neural signals captured by Si NW-FETs. The combination of mesh electronics with Si NW-FETs pushes the frontier of brain-machine interfacing towards a future where minimally invasive technology makes even voluntary implantation feasible.