Mechanical Characterization of Stretchable Ecoflex Thin Films for Microengineering Applications

Use of elastomers in microelectromechanical systems (MEMS) is increasing especially in wearable technology. Ecoflex is a silicone-based elastomer that has demonstrated significant interest in a variety of MEMS applications including wearables, stretchable electronics, and microfluidics. However, the manufacturing methods and their impact on their mechanical properties have not been systematically investigated. This paper investigates three different types of Ecoflex material (Gel, 00-10, 00-30) and methods of how to manufacture the material at the micro-scale and the impact that the manufacturing methods have on the material’s mechanical properties. The results demonstrate that the method of mixing and the curing temperature and procedure used significantly affect the mechanical properties. Spin mixed films had less variation and higher elastic modulus compared to hand mixed due to gas entrapment in the film, especially for higher viscosity Ecoflex. The paper also investigated mixing of multiple variations of Ecoflex materials to alter the mechanical properties which can be used to fine tune mechanical features. Thin films of Ecoflex were fabricated using spin coating techniques and patterned using O2 plasma. This paper describes manufacturing methods of making thin film Ecoflex samples for MEMS applications.