A touch screen system is configured to sense a proximate or actual touch made to a touch screen panel. In response thereto, an RF transmitter is actuated to emit RF energy. A stylus receives the emitted RF energy and includes an RF energy harvesting circuit that powers an enable circuit. The enable circuit generates an enable signal. The stylus responds to the enable signal by performing a sensing operation. The information collected in the sensing operation is then communicated over an RF communications link back to the touch screen system. The sensing operation preferably is a pressure sensing operation for detecting an applied pressure at an end of the stylus resulting from contact with the touch screen panel.