The invention relates to a shape-adaptive medical implant having at least one actuator, which the implant can be changed from a first implant geometry to a second implant geometry, the implant having a different geometric shape in the second implant geometry from that in the first implant geometry, wherein the actuator has a swellable chemical substance which swells when supplied with liquid, and wherein the implant which is designed to supply liquid present outside the implant to the swellable chemical substance. The invention also relates to the use of an electrical signal source.