We propose a highly sensitive pressure sensor using an elastic micro pyramid array with a gold-coated surface pressing on a resistive silicon beam. When a pressure was applied on the pyramid array, the deformation of each pyramid induced the larger contact area between each pyramid and the resistor. Since the pyramid array was coated by a gold layer, which had much lower resistivity than that of the silicon beam, the resistance of each contact area drastically decreased. Therefore the resistance between two electrodes of the silicon beam decreased. Our demonstrated sensor showed the non-linear response to the applied pressure, which was caused by the increase in elasticity of each pyramid as its deformation became larger. This non-linear property can be used as an advantage to enlarge the sensing range of the sensor. The sensitivity of our sensor for the pressure from 0 to 1 kPa was 0.61 kPa^-1. The resolution derived from the largest error, was 0.16 kPa.

References :
Nguyen Thanh Vinh, Kiyoshi Matsumoto, Isao Shimoyama,“High Sensitive 3D Tactile Sensor with the Structure of Elastic Pyramids on Piezoresistive Cantilevers,” The 26th IEEE International Conference on Micro Electro Mechanical Systems (MEMS '13), pp. 596 - 599 , Taipei, Taiwan, Jan. 20 - 24, 2013.[Proceedings]