Step 4: Attach sensor cables

Connections between hard and soft electronic components have largely been a hindrance to the integration of soft sensors in wearable applications. Establishing durable connections are a must for soft sensors to be useful in more robust wearable applications.

Leads from a thin 0.3mm diameter micro coaxial cable are attached to both electrodes and prevent parasitic capacitance or crosstalk. A secure mechanical bond is established between fabric and the cable leads using instant adhesive. 

The conductive filaments of the cable are fused to the fabric electrode surfaces with a thermoplastic film by applying 5-10 seconds of pressure with an iron. The thermoplastic film helps to secure the cables to the sensor and prevents delamination of the cables from the softer knit when it is stretched.