A multidirectional-sensitive inertial microswitch with electrophoretic polymer-metal composite fixed electrode for flexible contact

A multidirectional-sensitive inertial microswitch with polymer-metal composite fixed electrode has been designed and fabricated based on non-silicon surface micromachining in the present work. The microswitch can sense the applied accelerations from any directions in xoy plane and positive z-axis. Its vertical composite fixed electrode is completed by electroplating and electrophoretic deposition, which can realize a flexible contact between the electrodes and eliminate the bouncing phenomenon and prolong the contact time. As a result, the stability and reliability of the inertial switch could be greatly improved. The test results show that the threshold acceleration of the fabricated prototype is generally uniform (~70g) in different sensitive directions in xoy plane and z-axis. The contact time of the microswitch with composite fixed electrode is ~110μs in vertical direction, which is longer than that (~65μs) of one without polymer.