Integration of High Definition Display Technologies with Platinum Nanorod Microelectrodes for Large Scale in-vivo Recording and Stimulation

ABSTRACT We propose to develop novel neurorecording devices using sequential thin-film transistors that are capable of recording and stimulating brain activity with thousands of channels using only 8 wires and to demonstrate broadband recordings with large area coverage in fully awake, chronically implanted mice performing a decision task.

Our approach leverages the low temperature processing of the high mobility indium gallium zinc oxide (IGZO) thin film transistors (TFTs) on flexible substrates and uses chemically etched platinum nanorods (PtNRs), with nearly an ideal electrochemical interface for recording and stimulation that is of low impedance, stable/durable, and biocompatible, and which can be scaled to very tight pitches and high densities without compromising these properties.

Our efforts are staged with device, circuit, and electrochemical benchtop testing, followed by in vivo acute and chronic recordings in rodents and compare the fidelity of the recordings across all frequencies with side-by-side integrated passive electrodes.

In Aim 1, we will fabricate PtNR-IGZO multiplexing TFT arrays and perform comprehensive benchtop testing to validate sensitivity and stability by accelerated aging in the wet environment and validation of recording and stimulation in acute rat experiments.

In Aim 2, we will scale the novel PtNR-sequential TFT (PtNR-SEQTFT) arrays to record/stimulate from 5041/100 contacts using only 8 wires and validate their operation in benchtop and acute rat experiments.

In Aim 3, we will optimize the PtNR-SEQTFT for chronic implantation in mice and utilize two layouts: (1) Type I will have the TFTs located on top of the electrode grid as a necessary ?preclinical? step toward an eventual clinical device (human recordings are beyond the current scope); (2) Type II will have the TFTs arranged on the periphery of the array making the electrode array area optically transparent.

This device is targeted for basic neuroscience applications in awake, chronically implanted mice performing a decision task to demonstrate the ability of this novel technology to bridge single-cell neuronal activity to large-scale circuit phenomenon of brain waves and to cognitive performance.

This project will enable a new generation of microelectrode arrays with superior spatiotemporal resolution to provide a panoramic view of the coordinated brain activity across multiple regions that produces function.

It has potential to address fundamental neuroscience questions that require large scale recordings and to be advanced for future clinical applications.

The technology is also extendable to depth electrodes and is compatible with complementary multimodal brain interrogation technologies.

Our project builds around a true interdisciplinary integration of electrode interfaces and devices, circuit design, and neuroscience.

We will advance and disseminate this technology leveraging collaborative ties among the participating investigators and extensive resources and infrastructure at University of California San Diego (UCSD) and Boston University (BU).