A substrate that can be applied to a user's body part having a region of temporally-controlled elasticity that transitions between a first state and a second state when activated, wherein the first state is more relaxed than the second state, and the substrate can at least partially revert from the second state to the first state over an extended time period resulting from the temporally-controlled elasticity of the substrate, and wherein the substrate can apply a treatment/mechanical force to the body part, as the substrate transitions from the second state to the first state.