Development of a 3-DOF Micro Accelerometer with Wireless Readout

This paper describes the design, simulation and fabrication of a 3-DOF (degree of freedom) micro accelerometer with wireless readout system. The fabricated accelerometer has dimensions of 1000μm×1000μm×500μm (Length×Width×Thickness) and can detect three components of linear acceleration simultaneously. The sensitivities to X-axis, Y-axis and Z-axis are 30μV/g, 30μV/g and 23μV/g, respectively. A three input-channels wireless transceiver system has been developed and integrated with the sensing element to form a sensor node. The antenna has been designed to transmit the signal from sensor node to a server at a communication frequency of 2.4GHz over a distance of 20m. Three output signals, i.e. X-axis, Y-axis and Z-axis, from the accelerometer are transmitted to the server by time division multiplexing protocol. This allows our wireless sensor system to detect three components of acceleration independently.