Improved resistance stability for tactile sensor fabrication and investigation of the dispensing parameters of a nanocomposite material

Flexible electronics are showing a promising potential as the next technology revolution in electronics. Flexible tactile sensors, in particular, are getting a lot of attention and have been rapidly developing in the last few years. This is due, inter alia, to the large expansion of the wearable electronic market, flexible displays and the robotic applications where robots are developed to better interact with the external environment through physical contact via the use of tactile sensors. 3D printing technology is being more applied to develop electronic devices giving its numerous advantages. In this regard, the present work reports an improved strain sensor in terms of low and stable electrical resistance over a considerable period of time. The structure of the sensor consists of an elastomeric composite material composed of polydimethylsiloxane (PDMS) and a multi-walled carbon nanotubes (MWCNTs) conductive line deposited using the Direct-Write technique in between two elastomer substrates (PDMS). The developed sensor was able to display significant stability and relatively low resistance. The stability of the resistance throughout a period of 10 days, allowed the study of the dispensing parameters (such as the feed rate and the dispensing pressure of the conductive nanocomposite) influencing the dimensional characteristics (such as the dispensed line width and height). A numerical representation of the relation between the dispensing parameters and the obtained characteristics of the conductive line is presented.