Abstract: A new on chip system, named Acoustic Gym, to apply a surface acoustic wave (SAW) has been developed to control the swimming exercise of a large number of small animals such as C. elegans and Zebra fish, at desired intensities and durations. The SAW device consists of a circular chamber filled with fluid, which is placed in the center between a pair of offset interdigital transducers (IDTs) that are deposited on a piezoelectric substrate. Upon actuation from a radio frequency (RF) source, the SAW is generated and propagates along the substrate towards the microchamber. Once the SAW reaches the chamber, it induces an acoustic streaming in the fluid inside the chamber to stimulate swimming exercise of small animals. The streaming velocity can be precisely controlled via the RF signal input power, thus regulating the duration and intensity of exercise of the animals.