Polymeric Piezoresistive Microcantilevers With Reduced Electrical Variability

The observed electrical variability has limited the usage of the carbon black (CB)-SU8 (an epoxy polymer of di-glycidyl ether of bisphenol A) nanocomposite as a piezoresistive element in the microelectromechanical systems-based sensor applications. We report here a simple modification to the CB-SU8 nanocomposite preparation, which improves the dispersion of the CB particles in the SU8 polymer matrix creating a CB-SU8 photopatternable nanocomposite with a stable conductive network. The modified CB-SU8 nanocomposite was used as the piezoresistive element to fabricate microcantilever devices for strain sensing applications. Improved stability of these microcantilever devices is reflected from their electrical characterization. The electromechanical characterization of these microcantilevers demonstrated their piezoresistive behavior.