Jason Stoker, Dr. Ashutush Tiwari

Biocompatible Piezoelectric Materials

Department of Materials Science and Engineering, University of Utah

The search for biocompatible materials has always been an active topic of research. Piezoelectric materials are no exception. Currently, the most commonly used piezoelectric materials are lead-based, such as lead zirconate titinate (PZT), which is well known to have adverse effects on the body and environment. In order to realize safe implantable piezoelectric devices for in situ use as sensors, actuators, transducers, and ultimately power generation, sufficient biocompatible materials must be discovered. This paper proposes potassium niobium oxide (KNbO3) as a suitable replacement for PZT. Furthermore, this paper is the first to suggest that KNbO3 and devices based on KNbO3 might be used directly in the body. KNbO3 is a non-toxic biocompatible ferroelectric material. It possesses a very high electromechanical coupling factor with a high dielectric constant making it an excellent choice for implantable ferroelectric devices. Thin films of KNbO3 have been synthesized via pulsed laser deposition (PLD), on numerous substrates including MgO, Si, LaAlO3, Cu, TCO and SrTiO3. The structural and chemical properties of these films were characterized using x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and energy dispersive spectroscopy (EDS). The ferroelectric properties were established by measuring the hysteresis loop and the dielectric constant of the thin films, thus verifying the presence of high polarization, and polarizability. Bio-inertness and bacteria culturing experiments reinforce the herein proposed uses of KNbO3.