6. Drilling Mechanisms Using Piezoelectric Actuators Developed at Jet Propulsion Laboratory

Drilling mechanisms are widely used in many diverse fields including domestic, medical, industrial, military, geology and extraterrestrial applications (Bar-Cohen and Zacny in Drilling in Extreme Environments—Penetration and Sampling on Earth and Other Planets, Wiley—VCH, Hoboken, NJ, ISBN-10: 3527408525, ISBN-13: 9783527408528, 827 p, 2009). Generally, scientists and engineers have developed many types of drills with the majority of designs based on mechanical motion (rotary and/or percussive) of a cutting tool. These drills have been the result of the effort to deal with the challenges presented by the large variety of materials that need to be penetrated. Mechanical drills use a bit having a tip that interacts with the drilled material and applies forces over a small area to cause large shear and/or impact stresses for cutting or breaking the material. There is a wide variety of bit types that have been developed commercially, which can be readily purchased at local hardware stores. Increasingly, developers of drills for in situ exploration missions are seeking capabilities that address the complex challenges involved with extreme environments found at the planetary bodies where subsurface penetration is needed. This chapter is focused on the drilling mechanisms that are driven by piezoelectric actuators, which were developed by the authors at the Jet Propulsion Lab (JPL), Pasadena, CA.