AVS 53rd International Symposium
    MEMS and NEMS Monday Sessions
       Session MN+BI-MoA

Paper MN+BI-MoA6
Interfacial Properties of Polymer Interfaces for BioMEMS/NEMS Applications

Monday, November 13, 2006, 3:40 pm, Room 2007

Session: Surface and Interface Science of MEMS and NEMS
Presenter: M. Palacio, The Ohio State University
Authors: M. Palacio, The Ohio State University
B. Bhushan, The Ohio State University
N. Ferrell, The Ohio State University
Correspondent: Click to Email
Polymers are used in biological micro/nano electromechanical system (BioMEMS/NEMS) applications due to their desirable mechanical properties, biocompatibility and reduced cost relative to silicon microfabrication processes. Understanding the interfacial properties of the films that are used in BioMEMS/NEMS serves as a useful tool in obtaining higher device yield and greater mechanical reliability. In this study, two commonly used materials in BioMEMS/NEMS, polystyrene (PS) and glycidyl-ether-bisphenol-A novolac polymer (SU8) deposited on a silicon substrate, are investigated. The aim is to examine the delamination of the interfaces. Nanoindentation was employed on the PS/Si and SU8/Si film systems coated with a thin metallic layer of Cr to facilitate delamination. The interfacial adhesion energy was determined from measuring the size of the resulting delamination and the contact radius. Scale effects were investigated by comparing the behavior of systems with ultrathin (<100 nm) and thick (5 µm) PS films. In order to simulate the aqueous environment present in the human body, delamination experiments were performed on samples immersed in deionized water, and the interfacial adhesion energy was measured. To further simulate device operating conditions, delamination experiments were conducted at human body temperature by fitting the nanoindenter with a heating stage.