A touch panel comprising: a touch panel body comprising a first substrate and a second substrate spaced apart from the first substrate by a gap; a plurality of sensing electrode lines on the first substrate, for providing an output signal, wherein the sensing electrode lines are arranged in parallel; a plurality of driving electrode lines on the second substrate, wherein the driving electrode lines are perpendicular to the sensing electrode lines and are arranged in parallel, wherein the sensing electrode lines and driving electrode lines form a plurality of electrode pairs, wherein each of the electrode pairs forms a capacitive node at the intersections between the plurality of sensing electrode lines and the plurality of driving electrode lines; electrorheological fluid disposed in the gap between the first substrate and the second substrate; the touch panel device further comprising a driving unit (120,220) configured to apply a driving voltage for driving the electrorheological fluid to all or a portion of the plurality of electrode pairs via the driving electrode lines and a sensing unit arranged to apply a sensing signal sequentially to the plurality of driving electodes and the sensing electrode lines are arranged to provide the output signal, in response to the sensing signal, according to a change in capacitance at the corresponding capacitive node; wherein the sensing signal is a sensing voltage pulse, and the touch panel further comprises a combining unit which is arranged to combine the driving voltage with the sensing voltage pulse and apply the combined voltage to the electrode pairs; wherein the a sensing unit comprises: a charge pump having an input connected to at least one capacitive mode, wherein the input is connected to the sensing electrode line of the at least one capacitive node for accepting the output signal from the sensing electrode line of the at least one capacitive node in response to the sensing signal applied at the driving electrode line of the at least one capacitive node, wherein the output signal from the sensing electrode line is input to the charge pump as a charge source;wherein the sensing unit is arranged to determine whether there is a touch input on the touch panel based on an output voltage of the charge pump based on a change in capacitance due to a change in thickness of the gap between the first substrate and the second substrate, in response to the sensing signal. a touch panel body comprising a first substrate and a second substrate spaced apart from the first substrate by a gap; a plurality of sensing electrode lines on the first substrate, for providing an output signal, wherein the sensing electrode lines are arranged in parallel; a plurality of driving electrode lines on the second substrate, wherein the driving electrode lines are perpendicular to the sensing electrode lines and are arranged in parallel, wherein the sensing electrode lines and driving electrode lines form a plurality of electrode pairs, wherein each of the electrode pairs forms a capacitive node at the intersections between the plurality of sensing electrode lines and the plurality of driving electrode lines; electrorheological fluid disposed in the gap between the first substrate and the second substrate; the touch panel device further comprising a driving unit (120,220) configured to apply a driving voltage for driving the electrorheological fluid to all or a portion of the plurality of electrode pairs via the driving electrode lines and a sensing unit arranged to apply a sensing signal sequentially to the plurality of driving electodes and the sensing electrode lines are arranged to provide the output signal, in response to the sensing signal, according to a change in capacitance at the corresponding capacitive node; wherein the sensing signal is a sensing voltage pulse, and the touch panel further comprises a combining unit which is arranged to combine the driving voltage with the sensing voltage pulse and apply the combined voltage to the electrode pairs; wherein the a sensing unit comprises: a charge pump having an input connected to at least one capacitive mode, wherein the input is connected to the sensing electrode line of the at least one capacitive node for accepting the output signal from the sensing electrode line of the at least one capacitive node in response to the sensing signal applied at the driving electrode line of the at least one capacitive node, wherein the output signal from the sensing electrode line is input to the charge pump as a charge source;wherein the sensing unit is arranged to determine whether there is a touch input on the touch panel based on an output voltage of the charge pump based on a change in capacitance due to a change in thickness of the gap between the first substrate and the second substrate, in response to the sensing signal. a charge pump having an input connected to at least one capacitive mode, wherein the input is connected to the sensing electrode line of the at least one capacitive node for accepting the output signal from the sensing electrode line of the at least one capacitive node in response to the sensing signal applied at the driving electrode line of the at least one capacitive node, wherein the output signal from the sensing electrode line is input to the charge pump as a charge source;wherein the sensing unit is arranged to determine whether there is a touch input on the touch panel based on an output voltage of the charge pump based on a change in capacitance due to a change in thickness of the gap between the first substrate and the second substrate, in response to the sensing signal.