A method for ordering goods through the Internet is presented. The sensor has a load bearing member for receiving an input force to be sensed and associated circuitry for converting the input force into an output signal indicative of the input force. Firstly, bias settings at the gate, the source and the drain are controlled so that the device is under an initial state that an inversion layer is not formed and traps in the gate dielectric layer impose no confining effects on charges. The first and second differential output voltages are inputted to an active impedance bridge.