Abstract: An actuable truss with ordered or disordered planar or strut elements or pore walls may be seeded with tissue cells, wherein application of a magnetic field may result in mechanical strain on the cells and increased fluid flow in and out of the truss structure. Modified polymers, such as ?-Fe2O3/PLGA, may be used to form actuable scaffolds suitable for tissue engineering. It is also disclosed a device with a trap-door that may be remotely actuated by applying a magnetic field. Such a device may be employed to deliver and control the release of other micro-devices or materials such as drugs to a specific location inside the body of a human or an animal.