Miniaturized Actuator (image) Northwestern University Share Print E-Mail Caption The single, miniaturized actuators measure just 18 mm in diameter and 2.5 mm thick. Each actuator resonates most strongly at 200 cycles per second, where the skin exhibits maximum sensitivity. Credit Northwestern University Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.