Piezoelectric resonators based on self-assembled diphenylalanine microtubes

Piezoelectric actuation has been widely used in microelectromechanical devices including resonance-based biosensors, mass detectors, resonators, etc. These were mainly produced by micromachining of Si and deposited inorganic piezoelectrics based on metal oxides or perovskite-type materials which have to be further functionalized in order to be used in biological applications. In this work, we demonstrate piezoelectrically driven micromechanical resonators based on individual self-assembled diphenylalanine microtubes with strong intrinsic piezoelectric effect. Tubes of different diameters and lengths were grown from the solution and assembled on a rigid support. The conducting tip of the commercial atomic force microscope was then used to both excite vibrations and study resonance behavior. Efficient piezoelectric actuation at the fundamental resonance frequency approximate to 2.7 MHz was achieved with a quality factor of 114 for a microtube of 277 mu m long. A possibility of using piezoelectric dipeptides for biosensor applications is discussed. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4793417]