Hi everyone, very glad to see you here. My name is Kejie Zhao, a first year phd student working in Prof.Zhigang Suo's group (www.seas.harvard.edu/suo). My concentration is solid mechanics with the same name of this course, it also signifies its importance to my future research. I graduate from Xi'an Jiaotong University in China before coming to Harvard. There I obtained my bachelor and master degree in Engineering Mechanics and Solid Mechanics respectively. I have taken several courses related to ES240 at undergraduate level, i.e., elasticity mechanics, plasticity, non-linear continuum mechanics etc. Personally the major goal in this course is to cosolidate my background in solid mechanics and learn how to analysis engineering problems in mechanics insights. I am currently intrigued in the mechanics/fracture problems involved in battery recharge and discharge cyclings. We do think this field would bear a promising future.