A microchannel neural interface with embedded microwires targeting the peripheral nervous system

The essential purpose of neural interfaces is to record and stimulate neural activity. Careful analysis of neural signals allows them to be used to control technologies such as prosthetics and muscle stimulators that restore lost functionality caused by injury. Designing interfaces advanced enough to restore full functionality, however, is a challenge. Presented here is an animal study using the Texas regenerative peripheral nerve interface (TxNI), a novel neural interface device for communicating with peripheral nerves. Small extracellular potentials and concentration of current at the nodes of Ranvier increases the complexity of recording from axons. The TxNI is designed to obtain weak neural signals which are difficult to acquire using other techniques. The TxNI combines a PDMS (polydimethylsiloxane) microchannel scaffold with microwires (used as recording electrodes) embedded within the microchannels. Axonal regeneration is confined to the microchannels and electrodes are long enough to record from the nodes of Ranvier. Although several types of electrodes for peripheral nerve interfaces have been reported, they typically record unwanted signals from surrounding musculature and are subject to crosstalk. To address this, neural regeneration is directed through the TxNI in sealed microfluidic channels. The TxNI was successfully implanted in the rat sciatic nerve in the animal facility at UTPA. The details regarding its fabrication and implantation are described here. The present result is to be used to evaluate the effectiveness of the TxNI for use in advanced prosthetics. In particular, it aims to be used in a noninvasive brain-machine interface for bidirectional prosthetic arms.