Generally, a layer of light-induced shape-memory polymer (LISMP) is incorporated into touch input device in such way that its localized volume change caused by light activation of incidence light beam becomes detectable by sensing means of the touch input device. In accordance with the invention, one embodiment for the light activated input panel comprises two electrode layers respectively laid on two plates and separated by a predetermined gap and a layer of LISMP in between the two electrode layers. The layer of LISMP transforms illumination of incidence light beam into localized capacitance variation through localized volume change of LISMP activated by the illumination, which, in turn, is detected as a valid input by capacitive sensing means formed by the two electrode layers. Later, the localized volume change is restored through side light exposure by a side light source next to side of the layer of LISMP.