Journal of Bionic Engineering

Volume 14, Issue 4, October 2017, Pages 631-639

Jun Cai, Yingying Shi, Xinghao Li, Deyuan Zhang

School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, China

Abstract  Helical conductive particles have attracted much attention in preparing stretchable conductive materials because of their structural flexibility and uniform strain distribution under deformation. In this paper, Spirulina-templated silver micro springs were fabricated using electroless deposition of silver onto Spirulina surface. To investigate their potential application as con-ductive fillers for stretchable materials, they were mixed into polydimethylsiloxane (PDMS) uniformly, and then the mixture was spin coated on a polyfluortetraethylene (PTFE) plate to form a thin film, during which, micro springs tended to align its major axis along the radial direction of the plate. The tensile tests of micro springs were carried out using the film along the alignment direction of micro springs on the custom-made setup. Under the optimal condition of coating thickness of 0.67 μm, helical pitch of 29 μm and annealing temperature of 300 ?C, the average elongation of micro springs can reach up to ~106.9%, which indicates that the as-prepared Spirulina-templated silver micro springs are promising flexible conductive fillers for fabricating stretchable conductive materials.

Key words：micro springs      elongation      electroless deposition of silver      Spirulina      stretchable conductive fillers     
   
Full text is available at http://www.sciencedirect.com/science/article/pii/S1672652916604298