MIT researchers have developed a wearable patch that applies painless ultrasonic waves to the skin, creating tiny channels that drugs can pass through. This approach could lend itself to delivery of treatments for a variety of skin conditions, and could also be adapted to deliver hormones, muscle relaxants, and other drugs, offering comfort and control to patients and consumers. The lightweight, wearable patch is embedded with disc-shaped piezoelectric transducers that convert electric currents into mechanical energy. When activated, these transducers generate pressure waves in the fluid, creating bubbles that burst against the skin. The microjets produced by the bursting bubbles penetrate the skin’s tough outer layer, allowing drugs to enter the body.