Touch sensor : non conductive

Is there any touch sensor available which can detect touch by non conductive element ? . I have found that capacitive touch sensors work by detecting capacitance change when a conductive element like finger is contactef ,. But I need such touch sensor which can detect touch by any non conducting element like pen or wood stick . This type of touch sensors may be used in electric drum pad .

Thanks for reply .But I want somewhat different than flex sensor , as where will use I will have to bend the sensor . Tell me about other types of sensor .

You could glue a piezo element to the back side (bottom) of a material (wood or plastic or strong rubber).
That link was not only for flex sensors, but also force sensors and piezo.