A robust mechanically controlled atom transfer radical polymerization (mechano-ATRP) was developed by enhancing the interaction between piezoelectric nanoparticles and ATRP Cu catalysts. The interactions favor a mechanoinduced electron transfer from the surface of the nanoparticles to the deactivator Cu-II/L complex under ultrasonic agitation, promoting the formation of the activator Cu-I/L complex, thereby increasing the rate of the polymerization. This mechano-ATRP was carried out with a low loading of zinc oxide nanoparticles, providing a polymer with high end-group fidelity, predetermined molecular weight, and low dispersity. Propagation of the polymer chains was switched on/off in response to the ultrasound. The effects of the nature of the nanopartide, nanoparticle loading, and targeted degrees of polymerization were investigated to evaluate the mechanism of mechano-ATRP.