Development of MEMS device for effective and efficient in situ nanoscale tensile testing

Abstract

Nanomaterials have excellent properties in terms of mechanical, electrical, and optical properties. To apply nanomaterials to various applications, mechanical properties of nanomaterials should be measured and fracture mechanism should be analyzed. Among various experimental methods for measuring their mechanical properties, a promising one is an experimental method using MEMS (micro-electro mechanical systems). However, conventional MEMS device for tensile testing has a problem in analyzing fracture mechanism because the sample is immediately destroyed when a crack propagates during the tensile testing. In this thesis, a new MEMS device for tensile testing has developed to solve the problem. The new MEMS device has a higher mass of mobile part and higher spring constant compared to the conventional one. In the new MEMS device, crack propagation can be controlled because the crack driving force decreases with crack growth. The new MEMS device was fabricated and several problems with the new MEMS device were solved by modifying the detailed designs with creative ideas based on the dynamics simulation. The optimized MEMS device was tested, using DLC (Diamond-Like Carbon) which is brittle and amorphous material.