Implementation of a New Capacitive Touch Sensor Using the Nanoporous Anodic Aluminum Oxide (np-AAO) Structure

This study reports the implementation of a high-performance capacitive-type touch sensor by using the nanoporous anodic aluminum oxide (np-AAO) layer. The np-AAO layer is batch fabricated as the template to enable the direct formation of nanotexture metal film after deposition. The np-AAO is also exploited as the dielectric layer. Thus, the integration of np-AAO layer and the nanotexture metal film is employed to realize a metal-insulator-metal parallel-plate capacitance sensor. The sensitivity of the capacitive-type touch sensor is enhanced by the nanostructures. In application, the Au and Al metal layers and np-AAO are fabricated on Si substrate to form the parallel-plate capacitor. The testing demonstrates the np-AAO-based touch sensor has higher sensitivity. In addition, the detection of small object such as Drosophila using the fabricated np-AAO-based touch sensor is also demonstrated.