Implantable biomaterials, particularly hydrogel substrates with porous surfaces, and methods for enhancing the compatibility of biomaterials with living tissue, and for causing physical attachment between biomaterials and living tissues are provided. A metal chassis is arranged at the center of the metal frame on the back surface of the liquid crystal panel module. The controller is configured to control the turning-on and turning-off states of the first current source, the second current source and the first assist circuit.