Particle detecting device

A particle detecting device, comprising:

• a resonator comprising a box, a driving board, a piezoelectric vibrator and a suspended-particle sensor, wherein the box comprises a sampling chamber, an air inlet and a waterproof and breathable membrane, the air inlet is covered and attached by the waterproof and breathable membrane for filtering large particles with a particle size large than or equal to a threshold diameter contained in an external gas, so that screened and required-diameter particles with particle size smaller than the threshold diameter can pass through the waterproof and breathable membrane and be inhaled into the sampling chamber, and the driving board is disposed on bottom of the sampling chamber and comprises at least one passage hole disposed thereon, the piezoelectric vibrator is packaged on the driving board, wherein the suspended-particle sensor is packaged on the piezoelectric vibrator, and the suspended-particle sensor corresponds to the air inlet and maintains a spacing distance, wherein the driving board provides driving power and operation frequency to the piezoelectric vibrator to change a resonance frequency of the piezoelectric, and the screened and required-diameter particles are sedimented and collected on a surface of the suspended-particle sensor, so that a mass and a concentration of the screened and required-diameter particles can be detected;
• and
• a piezoelectric actuator disposed on, sealed and connected to one side of the resonator, so that the external gas is inhaled into the sampling chamber through the air inlet, flows and passes by the suspended-particle sensor, and is discharged out of the particle detecting device through the at least one passage hole and the piezoelectric actuator in sequence.