This device is an implantable neural stimulation and recording system designed for small animal in-vivoneuroscience. It is composed of two modules: the stimulation and recording system, and an external coil for wireless powering. Data transfer is carried out using a bluetooth SoC. Both modules are encapsulated in silicone. The stimulation module features an Omnetics connector to interface with multi-channel recording and stimulation electrodes. This interface can be encapsulated using fast-cure silicones in-situ during an experiment.

The purpose of this tool is to provide a versatile in-vivo experimental platform for peripheral neuroscience. Thanks to wireless powering the system can be used in studies using awake-behaving animals. A backpack with battery and wireless emitter or similar power source can be used to power the implantable interface.

A block diagram of the system is shown on the right. The interface can carry out both stimulation and recording using a custom ASIC. Commands and data sent to and from the ASIC pass through an ICE5LP-4K FPGA to a NRF52832 bluetooth-enabled microcontroller. Both the microcontroller and FPGA are reprogrammable over-the-air giving users improved flexibility over device functions and operation even after chronic in-vivoimplantation.

There are 32 recording and stimulation channels available on the ASIC, allowing for both simple and complex multi-electrode experimental setups. The chip was implemented in a high-voltage CMOS technology to increase voltage compliance. A regulated cascode output stage ensures high output resistance for the stimulator current source. 

Chip photo
Chip photo

Neural Interface Technical Specifications
Recording Stimulation 
 Channels 32 Channels 32 
 Resolution 10-bit  Voltage compliance ±9.25 V
 Gain 225 - 4725 Current range 6.3-315μA
 Sampling rate 16kHz Current resolution 6-bit
Summary of the table's contents