Novel flexible array pressure sensor

Abstract

The invention provides a novel flexible array pressure sensor, including an upper flexible thin layer, an upper electrode layer, a pressure-sensitive unit array, a lower electrode layer and a lower flexible thin layer in order from top to bottom. The pressure-sensitive unit array comprises n identical pressure-sensitive units, each pressure-sensitive unit comprises a pn junction and a pressure-sensitive film, and the pn junction is composed of a p-type semiconductor film and a n-type semiconductor film. Each pressure-sensitive unit of the flexible array pressure sensor is of a serially-connected structure composed of one pressure-sensitive film and one pn junction rectification diode. During measurement of resistance change of a single sensitive point, and the unilateral conduction feature of the pn junction rectification diode enables sensitive points on a sensor array not to form a current loop, so that the cross coupling between array resistors is effectively prevented. The sensor is small in size and light in weight, and the low-cost large-scale batch production is easy to achieve.

Description

technical field [0001] The invention belongs to the field of structural design of sensors, and in particular relates to a piezoresistive effect-based flexible array pressure sensor, which can be used to detect pressure distribution states in industrial production and medical rehabilitation. Background technique [0002] The array pressure sensor is a sensor used to detect the magnitude and distribution of pressure on objects when they are in contact with each other. It is suitable for objects with complex shapes and application environments. At present, the array pressure sensor put into use is mainly the array pressure sensor developed by Tekscan Company of the United States. The sensor is composed of two flexible polyester films printed with horizontal and vertical conductive lines. A longitudinal strip conductor is laid on the surface of a film. The width of the strip conductor can be flexibly designed according to the specific application, and the minimum can reach 0.6mm...

AI Technical Summary

Problems solved by technology

However, there is a serious cross-coupling problem in measuring the resistance value of a single point in a large-scale resistance network: when the resistance of the sensitive unit to be measured is selected by scanning the row line and the column line, the resistance around the selected resistance to be measured will pass through the row line and the column line. The column line and the resistance to be measured form a loop, and form a parallel relationship with the resistance to be measured, so that the actual value of the output resistance cannot be accurately measured

At present, the solutions to the cross-coupling problem mainly include: Tekscan company adds an operational amplifier to each row of the array resistor, using the principle of equal potential at the two input terminals of the amplifier, the column gating switch sequentially selects each column to provide the driving voltage, and the row The gating switch gates each row in turn to realize the row and column scanning of each point, thereby measuring the resistance of each sensitive point, but the circuit of this method is complicated, the power consumption is large, and a negative power supply is required; the Hefei Institute of Intelligent Machinery, Chinese Academy of Sciences proposed a The second scan method, that is, to eliminate the cross-coupling of the array resistance through two scans, the disadvantage of this method is that the pressure between the first scan and the second scan must not change, and the conditioning circuit is more complicated

Both of the above two solutions are to eliminate cross-coupling by adjusting the conditioning circuit at the back end of the sensor. There is no report on eliminating cross-coupling by improving the sensor structure.

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