Experimental Setup for Dynamic Analysis of Micro- and Nano-Mechanical Systems in Vacuum, Gas, and Liquid

An experimental setup to perform dynamic analysis of a micro- and nano-mechanical system in vacuum, gas, and liquid is presented. The setup mainly consists of a piezoelectric excitation part and the chamber that can be either evacuated for vacuum, or filled with gas or water. The design of the piezoelectric actuator was based on a Langevin transducer. The chamber is made out of materials that can sustain: vacuum, variety of gases and different types of liquids (mild acids, alkalies, common alcohols and oils). All the experiments were performed on commercial cantilevers used for contact and tapping mode Atomic Force Microscopy (AFM) with stiffness 0.2 N/m and 48 N/m, respectively, in vacuum, air and water. The performance of the setup was evaluated by comparing the measured actuator response to a finite element model. The frequency responses of the two AFM cantilevers measured were compared to analytical equations. A vacuum level of 0.6 mbar was obtained. The setup has a bandwidth of 10–550 kHz in vacuum and air, and a bandwidth of 50–550 kHz in liquid. The dynamic responses of the cantilevers show good agreement with theory in all media.

Design of a Dual-Resonance Excitation Langevin Piezoelectric Actuator Using Taguchi Method

For injection molding, knock-out pin will leave ejector marks on the parts of product. While making micro-structured components, the pin for normal ejector system is usually bigger than the micro-structured one. It would leave marks while part ejection process and it would even destroy the exterior of micro-structured components sometimes. In order to avoid this situation, this research is to design a Langevin transducer using the theory of Smooth Impact Drive Mechanism (SIDM) as a linear actuator. The dimensions of the Langevin piezoelectric actuator was determined using the Taguchi method to set the first and third minimum impedance frequency ratio at nearly 1:2. The mold equipped with the double layer Langevin transducer could demold the parts without knock-out pin in the plastic injection molding process.