Abstract: An air-pulse generating device includes a film structure including a flap pair. The flap pair includes a first flap and a second flap opposite to each other. The flap pair operates at an ultrasonic frequency, such that the air-pulse generating device produces a plurality of air pulses at an ultrasonic pulse rate. The flap pair possesses an initial deflection difference or exhibits an average displacement difference between the first flap and the second flap.

Abstract: An airflow generating device includes a first cell, disposed within a first region and a second cell, disposed within a second region. The first cell generates a first air pressure with a first polarity in the first region and the second cell generates a second air pressure with a second polarity in the second region. The second polarity is opposite to the first polarity. One of the first and second cells includes a film structure, which includes a flap pair. The flap pair includes a first flap and a second flap opposite to each other. The flap pair possesses an initial deflection difference or exhibits an average displacement difference between the first flap and the second flap. The flap pair operates at an ultrasonic frequency, such that the airflow generating device produces a plurality of air pulses at an ultrasonic pulse rate.

Abstract: An airflow generating device includes a first flap, a second flap, a first actuator, a second actuator and an anchor structure. The first flap and the second flap are opposite to each other in a top view viewing along a top-view direction. The first actuator is disposed on the first flap, and the second actuator is disposed on the second flap. The first flap includes a first anchored edge anchored on the anchor structure, and the first flap includes first free edges other than the first anchored edge which are non-anchored. The second flap includes a second anchored edge anchored on the anchor structure, and the second flap includes second free edges other than the second anchored edge which are non-anchored.

Abstract: An airflow generating device includes a first cell and a second cell. The first cell is disposed within a first region and generates a first air pressure with a first polarity. The second cell is disposed within a second region and generates a second air pressure with a second polarity. The second polarity is opposite to the first polarity.

Abstract: An air quality sensing module includes a chamber, an air quality sensor and an air pump. The air quality sensing module is disposed or to be disposed within a handheld device. The air pump produces an airflow toward or away from the chamber, for the air quality sensor to perform an air quality sensing operation. A direction of the airflow produced by the air pump within the handheld device is reversible.

Abstract: An air moving device includes a film structure, a first actuator and a second actuator. The film structure includes a flap pair, wherein the flap pair includes a first flap and a second flap opposite to each other. The first actuator is disposed on the first flap, and the second actuator is disposed on the second flap. The first actuator includes a first electrode and a second electrode, and the second actuator includes a third electrode and a fourth electrode. The first electrode receives a first demodulation signal and the third electrode receives a second demodulation signal, such that the flap pair performs a differential-mode movement. The second electrode and the fourth electrode receive a modulation signal, such that the flap pair performs a common-mode movement.

Abstract: The air-pulse generating device comprises a film structure, operating at an ultrasonic operating frequency, and a resonant chamber, formed on a side of the film structure. A resonance is formed within the resonance chamber. Due to the resonant chamber, the APG device has a peak on a frequency response of an acoustic property of the APG device at the ultrasonic operating frequency.

Abstract: An airflow generating package includes a base, a covering structure and a film structure. The film structure is disposed between the base and the covering structure, and includes a flap pair including a first flap and a second flap. The flap pair operates at an ultrasonic rate so that the airflow generating package produces an airflow. A first air opening is formed on the covering structure.

Abstract: An air quality sensing module includes a chamber, an air quality sensor and an air pump. The air quality sensing module is disposed or to be disposed within a handheld device. The air pump produces an airflow toward or away from the chamber, for the air quality sensor to perform an air quality sensing operation. A direction of the airflow produced by the air pump within the handheld device is reversible.

Abstract: A manufacturing method of an air-pulse generating device is provided. The manufacturing method includes: providing a wafer including a first layer and a second layer; patterning the first layer of the wafer to form a slit with a zigzagging pattern; and removing a first part of the second layer. A portion of the first layer above the removed first part of the second layer forms a film structure. The slit with the zigzagging pattern separates the film structure into a first flap and a second flap. The slit with the zigzagging pattern zigzags in a back-and-forth manner among a first direction and extends toward a second direction. The air-pulse generating device produces a plurality of air pulses by actuating the film structure.

Abstract: A cantilever structure includes an anchor portion and a film structure. The film structure covers over a cavity and vibrates within the cavity. A length of the film structure is less than a width of the film structure. The anchor portion includes at least one protrusion protruding toward the cavity, and the film structure is anchored on the anchor portion with the at least one protrusion.

Abstract: The air-pulse generating device comprises a film structure, operating at an ultrasonic operating frequency, and a resonant chamber, formed on a side of the film structure. A resonance is formed within the resonance chamber. Due to the resonant chamber, the APG device has a peak on a frequency response of an acoustic property of the APG device at the ultrasonic operating frequency.

Abstract: An air-pulse generating device includes a film structure. The film structure is driven to form an amplitude-modulated ultrasonic air pressure variation with an ultrasonic carrier frequency. The film structure is driven to form an opening at a rate synchronous with the ultrasonic carrier frequency. The air-pulse generating device produces a plurality of air pulses according to the amplitude-modulated ultrasonic air pressure variation, and the plurality of air pulses is asymmetric.

Abstract: A demodulation signal generator, coupled to an air-pulse generator comprising a flap pair, includes a resonance circuit. The resonance circuit produces a first demodulation signal and a second demodulation signal. The resonance circuit and the flap pair co-perform a resonance operation, such that the first demodulation signal and the second demodulation signal are generated via the co-performed resonance operation and have opposite polarity. The flap pair performs a differential movement to form an opening to perform a demodulation operation on a modulated air pressure variation.

Abstract: A device includes a microelectromechanical system (MEMS) sensor die comprising a deformable membrane, a MEMS heating element, and a substrate. The MEMS heating element is integrated within a same layer and a same plane as the deformable membrane. The MEMS heating element surrounds the deformable membrane and is separated from the deformable membrane through a trench. The MEMS heating element is configured to generate heat to heat up the deformable membrane. The substrate is coupled to the deformable membrane.

Abstract: An air-pulse generating device includes a film structure. The film structure is driven by a modulation-driving signal, so as to form an amplitude-modulated ultrasonic air pressure variation with an ultrasonic carrier frequency. The film structure is driven by a first demodulation-driving signal and a second demodulation-driving signal, so as to form an opening at a rate synchronous with the ultrasonic carrier frequency. The air-pulse generating device produces a plurality of air pulses according to the amplitude-modulated ultrasonic air pressure variation.

Abstract: A cantilever structure includes an anchor portion and a film structure. The film structure covers over a cavity and vibrates within the cavity. A length of the film structure is less than a width of the film structure. The anchor portion includes at least one protrusion protruding toward the cavity, and the film structure is anchored on the anchor portion with the at least one protrusion.

Abstract: An acoustic device includes a first sound producing component and a back cavity structure. The first sound producing component has a first front side and a first back side, wherein the first sound producing component is a high frequency sound unit, and the first front side faces a sound propagating opening of the acoustic device. The back cavity structure is connected to the first back side of the first sound producing component. The first sound producing component produces a first acoustic wave from the first front side towards the sound propagating opening, and the first sound producing component produces a second acoustic wave from the first back side towards a back cavity of the back cavity structure. The back cavity structure is configured to flatten a peak or a dip of a frequency response of the first sound producing component.

Abstract: An acoustic device includes a first sound producing component and a back cavity structure. The first sound producing component has a first front side and a first back side, wherein the first sound producing component is a high frequency sound unit, and the first front side faces a sound propagating opening of the acoustic device. The back cavity structure is connected to the first back side of the first sound producing component. The first sound producing component produces a first acoustic wave from the first front side towards the sound propagating opening, and the first sound producing component produces a second acoustic wave from the first back side towards a back cavity of the back cavity structure. The back cavity structure is configured to flatten a peak or a dip of a frequency response of the first sound producing component.

Abstract: A demodulation signal generator, coupled to an air-pulse generator comprising a flap pair, includes a resonance circuit. The resonance circuit produces a first demodulation signal and a second demodulation signal. The resonance circuit and the flap pair co-perform a resonance operation, such that the first demodulation signal and the second demodulation signal are generated via the co-performed resonance operation and have opposite polarity. The flap pair performs a differential movement to form an opening to perform a demodulation operation on a modulated air pressure variation.