Capacitive sensors measure changes in capacitance to detect differences in their environment. They are commonly used as touchscreens to detect the location of fi ngers or a stylus on the screens of smart phones, tablets, computer screens, music players, and computer touch pads, though many other uses exist in scientifi c research and industry. XFdtd® can compute the capacitance of complex sensor designs, allowing the designer to choose the best geometry for their needs without prototyping.