1September 1994 to1March 1995,1September 1996 to1March 1998, invited by Kloster University of Technology and Humboldt Foundation, engaged in scientific research in optical mechanics.
1April 1998-1March 1999 was invited by the postdoctoral fund of Japan National Institute of Science and Technology to study the mechanical behavior of materials by electron beam moire method.
1April, 1999 to June, 200 1, engaged in the moire method research of high resolution scanning electron microscope in Nanyang Technological University, Singapore. The principle of measuring nano-deformation by atomic force microscope moire method (nano-moire method) is put forward for the first time, and it is applied to the residual strain analysis of graphite irradiated by laser.
From July 20065438 to February 2002, he worked in the Advanced Thin Film Technology Center of new york State University, USA, and studied the mechanical behavior of MEMS by micro-moire method.
In March 2002, he returned to work in the Department of Engineering Mechanics in Tsinghua University.