A pseudo-piezoelectric d33 device includes a nano-gap, and a pair of integral and substantially parallel electrodes having a first sensing electrode and a second sensing electrode. The first sensing electrode and the second sensing electrode constitute a receiver. The nano-gap is disposed between the first sensing electrode and the second sensing electrode. An initial height of the nano-gap is smaller than or equal to 100 nanometers. The nano-gap is formed after a thermal reaction between a semiconductor material and a metal material to form a semiconductor-metal compound. The first sensing electrode of the receiver includes the semiconductor-metal compound to provide an integral capacitive sensing electrode to sense a capacitance change with the second sensing electrode and generate a sensing signal.