Stretchable gold nanowire-based cuff electrodes for low-voltage peripheral nerve stimulation

Objective. Electrical stimulation of the peripheral nervous system (PNS) can treat various diseases and disorders, including the healing process after nerve injury. A major challenge when designing electrodes for PNS stimulation is the mechanical mismatch between the nerve and the device, which can lead to non-conformal contact, tissue damage and inefficient stimulation due to current leakage. Soft and stretchable cuff electrodes promise to tackle these challenges but often have limited performance and rely on unconventional materials. The aim of this study is to develop a high performance soft and stretchable cuff electrode based on inert materials for low-voltage nerve stimulation. Approach. We developed 50 mu m thick stretchable cuff electrodes based on silicone rubber, gold nanowire conductors and platinum coated nanowire electrodes. The electrode performance was characterized under strain cycling to assess the durability of the electrodes. The stimulation capability of the cuff electrodes was evaluated in an in vivo sciatic nerve rat model by measuring the electromyography response to various stimulation pulses. Main results. The stretchable cuff electrodes showed excellent stability for 50% strain cycling and one million stimulation pulses. Saturated homogeneous stimulation of the sciatic nerve was achieved at only 200 mV due to the excellent conformability of the electrodes, the low conductor resistance (0.3 Ohm sq(-1)), and the low electrode impedance. Significance. The developed stretchable cuff electrode combines favourable mechanical properties and good electrode performance with inert and stable materials, making it ideal for low power supply applications within bioelectronic medicine.Funding Agencies|Swedish Foundation for Strategic Research, Swedens Innovation Agency (VINNOVA); Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO Mat LiU) [2009 00971]