In the growing field of mechanobiology, artificial mechano-reactive systems play an essential role in the generation of mechanical forces and control of material deformations. Free-standing magnetic nanoparticles have been studied for the mechanical stimulation of living cells. Magnetic composite materials are also used to mimic muscles at macroscale. In this study, a new magnetically actuated membrane is focused, which can be used for various applications in soft robotics or as a bioreactor. It consists of a few microns thick polydimethylsiloxane (PDMS) membrane in which an array of magnetic microdisks is embedded. These membranes have a large tuneable flexibility, and they are transparent, biocompatible, and waterproof. They are usable in biology and optics, both potentially combined. The membrane deformations under magnetic field have been experimentally characterized and modeled. By growing pancreatic cells on such membranes, it has been demonstrated that insulin production from the cells can be enhanced thanks to the mechanical stimulation of the cells provided by the actuated membrane.