Development of a stretching setup for the characterization of soft neural electrodes

Introduction

Electrodes are the key component for reliably interfacing electronics with the nervous tissue in neuroprosthetic applications. Conventional electrodes are made from rigid materials. However, several studies have shown that neural interfaces made from soft materials show a better acceptance by the body and less averse tissue responses. This is mainly due to micromovements in the living body which cause stress at the nerve-electrode interface and thereby damage the surrounding tissue. To ensure the long-term stability of soft electrodes after implantation, several mechanical and electrochemical tests need to be carried out during development and characterization of the devices. The aim of this is to build an experimental setup and developt appropriate characterization protocols which will be used for testing our neural interfaces.

Aim & research methods

In this project, we want develop a setup which can be used to stretch soft electrodes over 10-105 cycles and measure the corresponding changes in the resistance of their interconnects. Furthermore, the setup should be able to be interfaced with a potentiostat so that the electrodes can be characterized electrochemically while subjected to strain. The project will thus include:

  1. Design of the setup with a CAD tool and implementation of the setup.
  2. Design of the electronics to control the stretching mechanism and to monitor all relevant data.
  3. Writing a graphical user interface for controlling the stretching mechanism and displaying the change in resistance vs. the applied strain.

You will be introduced in an interdisciplinary working environment and will learn the following techniques:

  1. Establishing a complete experimental test setup.
  2. Electrochemical characterization techniques for electrode-electrolyte interfaces.
  3. Electromechanical characterization techniques for soft conductors.

Requirements

  1. Dedication and motivation to work on an interdisciplinary research topic.
  2. Experience with a CAD tool (Solidworks is preferred).
  3. Experience in electronics design.
  4. Experience with PCB design software (Altium Designer, Eagle, or equivalent).
  5. Experience in programming microcontrollers and or system-on-chip.

Possible starting date & further information

Potential starting date is as soon as possible. For further details and application contact Korkut Terkan in person, via email or by phone.

Note: This project can also be carried out in the framework of an internship.

References

  1. R. Moser u. a., „From Playroom to Lab: Tough Stretchable Electronics Analyzed with a Tabletop Tensile Tester Made from Toy-Bricks“, Adv. Sci., Bd. 3, Nr. 4, S. 1500396, Apr. 2016.
  2. S. P. Lacour, G. Courtine, und J. Guck, „Materials and technologies for soft implantable neuroprostheses“, Nat. Rev. Mater., Bd. 1, S. 16063, Sep. 2016.
  3. S. F. Cogan, „Neural Stimulation and Recording Electrodes“, Annu. Rev. Biomed. Eng., Bd. 10, Nr. 1, S. 275–309, 2008.