Screen printed fabric electrode array for wearable functional electrical stimulation

Functional electrical stimulation (FES) activates nerves using electrical currents, and is widely used in medical applications to assist movement of patients with central nervous system lesions. The recent emergence of small electrode arrays enables greater muscle selectivity and reduces fatigue compared to the use of traditional large electrodes; however existing fabrication techniques are expensive and have limited flexibility and comfort which limits patient uptake. This work presents a screen printed flexible and breathable fabric electrode array (FEA) which consists of four printed functional layers. Successful operation has been demonstrated by stimulating an optimised selection of electrodes in order to achieve clinically relevant reference postures (‘pointing’, ‘pinch’ and ‘open hand’). The materials with skin contact used in FEA have been cytotoxicity tested to establish that they are biocompatible. The FEA demonstrates the potential for printable polymer materials to realise comfortable, wearable and cost effective functional systems in healthcare applications.