In a recent Nature Chemistry paper, the Esser-Kahn lab showed that a radical polymerization of acrylate monomers can be initiated and controlled by ultrasound. The ultrasonic agitation of piezoelectric nanoparticles was used to mediate an electrochemical reduction of a Cu(II)-complex to generate the activator of copper catalyzed atom transfer radical polymerization. Mechanical energy can now, therefore, be used to both grow and destroy polymeric chains.