The invention provides a flexible piezoresistive touch
sensor array and a preparation method thereof. The
sensor array comprises N*N separated piezoresistive
layers and a coplanar
electrode layer. The piezoresistive
layers are arranged on the coplanar
electrode layer. Each piezoresistive layer comprises an upper finger pressing layer, a middle sensitive layer and a bottom sensitive layer, wherein the three
layers are each provided with a micro
pyramid; the coplanar
electrode layer comprises a
polymer electrode substrate and N*N gold electrode pairs located on the
polymer electrode substrate. The piezoresistive layers adopt
polymer films with the micro
pyramid, and due to the three-layer structure, the sensitivity of the sensor at the low-
voltage region can be greatly improved. In addition, in order to overcome the defect that a traditional touch sensor is large in
crosstalk due to a sandwiched structure, the coplanar electrode layer is adopted, all electrodes are located on the same plane, each piezoresistive layer is attached to the corresponding
electrode pair, the piezoresistive units are completely separated, and the sensitivity and anti-interference capacity of the sensor are effectively improved.