Patterning conductive PDMS nanocomposite in an elastomer using microcontact printing

Abstract

This paper introduces a simple method of embedding conductive and flexible elastomer micropatterns into a bulk elastomer. Employing microcontact printing and cast molding techniques, patterns consisting of conductive poly(dimethylsiloxane) (PDMS) composites mixed with multi-walled carbon nanotubes (MWCNTs) are embedded into bulk PDMS to form all-elastomer devices. To pattern conductive composites, a micromachined printing mold is utilized to transfer composite ink from a spin-coated thin layer to another substrate. Distinct from previously reported approaches, the printing mold in this technique, once fabricated, can be repeatedly used to generate new patterns and therefore greatly simplifies the device fabrication process and improves its efficiency. Manufactured devices with embedded conductive patterns exhibit excellent mechanical flexibility. With characterization of printing reliability, electrical conductivity of the composites is also shown with different loading percentages of MWCNTs. Furthermore, a simple strain gauge was fabricated and tested to demonstrate the potential applications of embedded conductive patterns. Overall, this approach demonstrates feasibility to be a simple method to pattern conductive elastomers that work as electrodes or sensing probes in PDMS-based devices. With further development, this technology yields many potential applications in lab-on-a-chip systems.

Effects of Fumed and Mesoporous Silica Nanoparticles on the Properties of Sylgard 184 Polydimethylsiloxane

“…In order to obviate the agglomeration and achieve a homogeneous dispersion, magnetic stirring and sonication were often used [13,19]. In addition, organic solvents were often used to help the dispersion of nanoparticles, such as toluene [21,22] and xylene [13,19]. Our group once used toluene to dilute PDMS for making a thin film [23], hence, here, toluene was also chosen as the dilute solvent.…”

Stretchable conducting gold films prepared with composite MWNT/PDMS substrates

“…The reaction between the MWNT and the PDMS cure is demonstrated independently with swelling measurements as well as spectroscopic and thermal data. Composites prepared by in situ curing of PDMS with the presence of CNT have been prepared by a variety of methods, [13][14][15][16][17][18][19][20] with a number of reports showing a reaction between CNT and PDMS. 19,20 In the present study, the identification of a reaction between the curing agent and the MWNT suggests that the C=C bonds at the surface of MWMT, just as vinyl bonds in the base, can react with the Si-H bonds in the curing agent.…”

Embedding conductive patterns of elastomer nanocomposite with the assist of laser ablation

“…The fabrication of embedded nanocomposite sensors starts with the mixing of carbon nanotubes with PDMS, the process of which has been previously reported in detail (Liu and Choi 2009). Briefly, multi-walled carbon nanotubes (MWCNTs, from Cheap Tubes Inc., inner diameter (Hwang et al 2011).…”

“…While lithography provided a way of defining micropatterns, it required an optical mask for each new pattern design and often needed cleanroom access. To save fabrication time and cost (Lawes 2006), we previously reported an alternative approach which used microcontact printing to pattern PDMS nanocomposite (Liu and Choi 2009). Conductive ''ink'' was directly transferred from one substrate to another using a printing stamp.…”