Tactile array sensor for manipulator based on the barometric chips

Abstract

This article presents a new method of using barometric chips to make tactile array sensor for manipulator. The barometric chip can detect and convert analog air pressure to digital signal and calculate the value of surface air pressure. First we design appropriate circuits with the PCB technology and mount the chips on the board, then we manufacture a silica gel air cell on each chip. In the way, the load stress applied on the silica gel surface can be converted to air pressure through the air cells. Using a force gauge we succeed determining the specific relationship of the air pressure versus the load stress. The result shows a high linearity with the R2 coefficient is 0.9951. The sensor chip has a small size (2.5 × 2.5 × 1.0 mm), low power consumption (4μA), high sample rates (40Hz) and is inexpensive(US$ 2.06 per chip). Besides, it can detect the temperature directly. The elastic silica gel also acts as a robust and compliant contact surface and protection. This method can enable progress for tactile sensors in applying to the cognitive robotic manipulator and various fields where the tactile information is valuable.