An energy harvesting apparatus comprising: a piezoelectric convertor layer having opposing first and second faces; and a proximal first piezoresistive layer being in electrical communication with the first face of the piezoelectric convertor layer, the apparatus being configured such that when the piezoelectric convertor layer is deformed to generate charge, the proximal piezoresistive layer is configured to control the flow of charge from the piezoelectric convertor layer, wherein the apparatus further comprises: a first circuit portion electrically connected to the first face of the piezoelectric convertor layer via the first piezoresistive layer, and the opposing second face of the piezoelectric convertor layer, the first circuit portion being configured to store charge generated by the piezoelectric convertor layer; and a second circuit portion electrically connected to the first face of the piezoelectric convertor layer and the opposing second face of the piezoelectric convertor layer, the second circuit portion being configured to enable charge to be equalised between the opposing first and second faces of the piezoelectric convertor layer, wherein the second circuit portion comprises a resistor configured to resist charge equalisation between the opposing first and second faces of the piezoelectric convertor layer, the resistance of the first piezoresistive layer being less than the resistance of the resistor when the piezoelectric convertor layer is deformed, and being greater than the resistance of the resistor when the piezoelectric convertor layer is not deformed. a piezoelectric convertor layer having opposing first and second faces; and a proximal first piezoresistive layer being in electrical communication with the first face of the piezoelectric convertor layer, the apparatus being configured such that when the piezoelectric convertor layer is deformed to generate charge, the proximal piezoresistive layer is configured to control the flow of charge from the piezoelectric convertor layer, wherein the apparatus further comprises: a first circuit portion electrically connected to the first face of the piezoelectric convertor layer via the first piezoresistive layer, and the opposing second face of the piezoelectric convertor layer, the first circuit portion being configured to store charge generated by the piezoelectric convertor layer; and a second circuit portion electrically connected to the first face of the piezoelectric convertor layer and the opposing second face of the piezoelectric convertor layer, the second circuit portion being configured to enable charge to be equalised between the opposing first and second faces of the piezoelectric convertor layer, wherein the second circuit portion comprises a resistor configured to resist charge equalisation between the opposing first and second faces of the piezoelectric convertor layer, the resistance of the first piezoresistive layer being less than the resistance of the resistor when the piezoelectric convertor layer is deformed, and being greater than the resistance of the resistor when the piezoelectric convertor layer is not deformed. a first circuit portion electrically connected to the first face of the piezoelectric convertor layer via the first piezoresistive layer, and the opposing second face of the piezoelectric convertor layer, the first circuit portion being configured to store charge generated by the piezoelectric convertor layer; and a second circuit portion electrically connected to the first face of the piezoelectric convertor layer and the opposing second face of the piezoelectric convertor layer, the second circuit portion being configured to enable charge to be equalised between the opposing first and second faces of the piezoelectric convertor layer, wherein the second circuit portion comprises a resistor configured to resist charge equalisation between the opposing first and second faces of the piezoelectric convertor layer, the resistance of the first piezoresistive layer being less than the resistance of the resistor when the piezoelectric convertor layer is deformed, and being greater than the resistance of the resistor when the piezoelectric convertor layer is not deformed.