Mr. Liu worked as a mechanical designer in Qinhuangdao Fanghua Essem Machinery Co., Ltd., responsible for the complete design of non-standard mechanical equipment；

Previously, he served as a research and development designer and project leader in ABNORD (Beijing) Medical Technology Co., Ltd., responsible for the structural research and development, mechanical performance testing, management and training of nanoscale processing equipment, project leader in the project of intraocular implanted myopia lenses, and patent layout analysis of competitor products.