Authors: R. Amarasinghe, D.V. Dao, S. Sugiyama
Affilation: Ritsumeikan University, Japan
Pages: 631 - 634
Keywords: sub-millimeter, solid-state, accelerometer, piezoresistive
This paper presents design, fabrication and characterization of miniaturized one-axis single crystal solid-state accelerometers with Nanometer Stress Concentration Region (NSCR) on piezoresistive sensing elements utilizing MEMS bulk micromachining techniques and design, simulation of new sub-millimeter 3-axis accelerometer for wearable sensing applications. Recently, Wearable acceleration sensors have become an inexpensive option to measure the movements and positions of a person. Other techniques that use environmental sensors such as ultrasound trackers or vision-based methods need full line of sight or a local setup, and it is complicated to access this data from a wearable computer’s perspective. However, overall physical dimensions of acceleration sensors are a main limitation of development of wearable sensors. These acceleration sensors have found many important and interesting applications, there are many more especially in the biomedical domain, where the >1mmx1mm overall device area of the MEMS accelerometers are barrier to use. Some reported miniaturized accelerometers are sulfuring from low sensitivity as piezoresistor can not feel maximum stress because of small effective mass. For that reason this accelerometer has fabricated as small as with overall dimensions 950umX850umX450um, length width and thickness, respectively and new sub-millimeter structure which has an overall chip size less than 700 m 700 m has been discussed. Various techniques have been employed by designers of accelerometers all over the world to enhance sensitivity and also maintain higher resonant frequency. These techniques are mostly concentrated either on various shapes of Proof-mass or on different beam type of structures for sensors. In this research, a deliberate introduction of Nanometer Stress Concentration Region (NSCR) on the piezoresistors fabricated by combination of thermal diffusion, focus ion beam (FIB) process is one of novel technique of increasing sensitivity of piezoresistive type of sensors. Secondly, a novel 3-axis sub-millimeter accelerometer with high sensitivity beam structure has been designed simulated.