A lot work has been done/published in the area of in-situ mechanical testing using electron microscopy. Please list which, according to what you feel has had a significant impact. Here are two in my opinion:
Uchic, M. D., Dimiduk, D. M., Florando, J. N., & Nix, W. D. (2004). Sample dimensions influence strength and crystal plasticity. Science, 305(5686), 986-989.
Shan, Z. W., Mishra, R. K., Asif, S. S., Warren, O. L., & Minor, A. M. (2007). Mechanical annealing and source-limited deformation in submicrometre-diameter Ni crystals. Nature materials, 7(2), 115-119.