Air pump

Abstract

An air quality sensing module includes a cavity, 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 generates airflow toward or away from the cavity to cause the air quality sensor to perform air quality sensing operations. The direction of the airflow generated by the air pump within the handheld device is reversible.

Description

[Technical Field]

[0001] This invention relates to an air quality sensing module and an air pump, and more particularly to an air quality sensing module and an air pump in a handheld device. [Previous Technology]

[0002] Air quality is generally taken for granted as playing a vital role in our health and well-being. The air we breathe is a complex mixture of gases and particulate matter, and the presence of pollutants can have serious short-term and long-term health consequences.

[0003] Poor air quality is linked to a range of respiratory and cardiovascular problems, including asthma, bronchitis, lung cancer, heart disease, and stroke. Harmful pollutants (such as particulate matter (e.g., PM2.5 and PM10), ozone (O3), nitrogen dioxide (NO2), and sulfur dioxide (SO2)) can irritate the trachea, reduce lung function, and cause inflammation. Vulnerable groups such as children, the elderly, and those with pre-existing health conditions are particularly vulnerable to the adverse effects of air pollution.

[0004] Therefore, air quality sensors are essential for this group.

[0005] Unfortunately, existing air quality sensors are often bulky and inconvenient for personal use, which limits their ability to provide real-time, close-range, or even breathing zone air quality data, which is crucial for personal health decisions.

[0006] For example, current gas / dust / particle sensors are typically used in air purifiers or vacuum cleaners, and are driven by fans in these devices to provide sufficient airflow. Since the fan module (whether with or without blades) requires a rotor to drive it, gas / particle sensors are difficult to use at close range due to their size and noise issues.

[0007] On the other hand, carbon monoxide (CO) sensors require air diffusion and sufficient concentration to achieve adequate accuracy and an acceptable response. Generally, measuring the air and obtaining data takes more than 30 seconds, so such a slow response is not good enough for immediate use. From another perspective, carbon monoxide sensors are typically placed in kitchens or places where fires may not burn completely (meaning the sensor is attached to the machine). If the sensor could follow the person / user and issue a warning when they encounter an environment with high (or relatively high) carbon monoxide concentrations, it would make the person / user safer. Therefore, this means that close-range use is crucial.

[0008] Accordingly, there is an urgent need to improve the existing technology. [Summary of the Invention]

[0009] Therefore, the main object of the present invention is to provide an air quality sensing module in a handheld device, and the present invention also provides a related air pump.

[0010] One embodiment of the present invention discloses an air quality sensing module, which includes a cavity, an air quality sensor, and an air pump. The air quality sensing module is disposed or to be disposed in a handheld device. The air pump generates airflow toward or away from the cavity to cause the air quality sensor to perform air quality sensing operations. The direction of the airflow generated by the air pump in the handheld device is reversible.

[0011] One embodiment of the present invention discloses an air pump comprising a first flap, a second flap, a first actuator, a second actuator, and an anchoring structure. The first flap and the second flap are opposite to each other in a top view along a planar 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 anchoring edge anchored to the anchoring structure, and the first flap includes a plurality of non-anchored first free edges in addition to the first anchoring edge. The second flap includes a second anchoring edge anchored to the anchoring structure, and the second flap includes a plurality of non-anchored second free edges in addition to the second anchoring edge.

[0012] After reading the following detailed description of embodiments illustrated with various figures, the object of the present invention should be clear to those skilled in the art.

Implementation Method

[0014] In this invention, the technical features described in the embodiments can be mixed or combined in various ways, as long as they do not conflict.

[0015] In this invention, the airflow generating element is used to generate airflow, wherein the airflow generating element can be applied to applications such as cooling, drying, dehumidification, heat dissipation, ventilation, air sampling, extraction and / or exhaust by generating airflow. In this invention, the airflow generating element can be designed according to requirements, and the airflow generating element can be formed by any suitable method. Some embodiments of the airflow generating element will be described below.

[0016] For example, the airflow generating element may be an air pump or an airflow generating chip, wherein the air pump or airflow generating chip may be formed by a semiconductor process. For example, the airflow generating chip may be a microelectromechanical system (MEMS) chip and includes MEMS structures, but is not limited thereto.

[0017] In this invention, "air pump" and "airflow generating element / chip" refer to the same element and the names can be used interchangeably. In addition, "air pump" and / or "airflow generating element / chip" can realize the concept of fan-on-chip, that is, a small-sized element capable of generating airflow (e.g., as small as the chip size, where the chip length / width can be less than 15 millimeters (mm)).

[0018] Due to its small size (e.g., as small as a chip size, where the chip length / width can be less than 15 mm), an air quality sensing module containing an airflow generating element / chip can be placed in a handheld electronic device to achieve instantaneous, close-range air quality sensing.

[0019] Please refer to Figures 1 and 2. Figure 1 is a cross-sectional schematic diagram of an air pump according to an embodiment of the present invention, and Figure 2 is a cross-sectional schematic diagram of the common-mode motion and differential-mode motion of an air pump according to an embodiment of the present invention, wherein the air pump AFC shown in Figure 1 is in an intermediate state S1. As shown in Figures 1 and 2, the air pump AFC is used to generate airflow. In some embodiments, the air pump AFC can be used to generate multiple air pulses, and the airflow can be composed of air pulses, wherein the air pump AFC can generate air pulses at any suitable pulse rate. For example, the air pump AFC can generate air pulses at ultrasonic frequencies (ultrasonic pulse rates) higher than the maximum audible frequency of humans (e.g., 16 kHz, 20 kHz, or 22 kHz), so that the user cannot hear the operation of the air pump AFC used to generate airflow and / or air pulses, but this is not a limitation.

[0020] As shown in Figure 1, the air pump AFC may include at least one anchoring structure AR and at least one membrane structure 10, wherein the membrane structure 10 is anchored to the anchoring structure AR, and the anchoring structure AR may be disposed on the outside of the membrane structure 10. The membrane structure 10 and the anchoring structure AR may include any suitable material. In some embodiments, the membrane structure 10 and the anchoring structure AR may each include silicon (e.g., monocrystalline silicon or polycrystalline silicon), silicon compounds (e.g., silicon carbide, silicon oxide), germanium, germanium compounds, gallium, gallium compounds (e.g., gallium nitride, gallium arsenide), other suitable materials, or combinations thereof, but are not limited thereto. In some embodiments, the membrane structure 10 and the anchoring structure AR may have the same material.

[0021] During operation of the air pump AFC, the membrane structure 10 can be actuated to move, while the anchoring structure AR can remain stationary. In other words, during operation of the air pump AFC, the anchoring structure AR can be a fixed end (or fixed edge) relative to the membrane structure 10. In some embodiments, the membrane structure 10 can be actuated to move upward and downward, but is not limited thereto. In this invention, the terms "moving upward" and "moving downward" mean that the membrane structure 10 moves substantially along the direction Z. Additionally, "upward" can refer to the direction Z (i.e., the +Z direction), while "downward" can refer to a direction opposite to the direction Z (i.e., the -Z direction). In other words, the actuation direction of the membrane structure 10 is parallel to the direction Z. In one embodiment, the direction Z can be a vertical direction and / or a top-view direction.

[0022] As shown in Figure 1, the membrane structure 10 of the air pump AFC includes at least one slit SL. The membrane structure 10 can be divided into multiple lobes (e.g., lobes 101, 103) through the slit SL. That is, the lobes can be separated from each other through the slit SL, and the slit SL can be the boundary of the lobes. The number of lobes can be designed according to requirements. For example, as shown in Figure 1, the membrane structure 10 can be divided into lobes 101 and lobes 103 through the slit SL. The two lobes 101 and 103 can be arranged opposite each other, and at least one slit SL is located between the two lobes 101 and 103. It should be noted that the two opposite lobes 101 and 103 can form a lobe pair in the membrane structure 10.

[0023] In Figure 1, each of the lobes 101 and 103 of the membrane structure 10 has at least one anchored edge (or anchored end) and at least one free edge (free end). The anchored edge is anchored to the anchoring structure AR, and the free edge is not permanently anchored to any element of the air pump AFC. The anchored edge and free edge of each lobe 101 and 103 can be designed as required. For example (as shown in Figure 1), the slit SL can define a free edge of lobe 101 (e.g., a first free edge 101n1) and a free edge of lobe 103 (e.g., a second free edge 103n1). This free edge of lobe 101 (e.g., the first free edge 101n1) can be relative to the anchored edge of lobe 101, and this free edge of lobe 103 (e.g., the second free edge 103n1) can be relative to the anchored edge of lobe 103, but is not limited thereto.

[0024] In this invention, the number of slits SL included in the membrane structure 10 can be adjusted as needed, and the slits SL can be set at any suitable location in the membrane structure 10 and have any suitable top view pattern. For example, the slits SL can be straight slits, curved slits, combinations of straight slits, combinations of curved slits, or combinations of straight slits and curved slits.

[0025] The air pump AFC may include an actuator AT for actuating the membrane structure 10 to generate airflow and / or air pulses, wherein the actuator AT may be disposed in any suitable location, and the location of the actuator AT may be related to the actuation mode of the actuator AT. For example, in Figure 1, the actuator AT may overlap the membrane structure 10 in the Z direction, but is not limited thereto. For example, in Figure 1, the actuator AT may be disposed on the membrane structure 10, but is not limited thereto. For example, in Figure 1, the actuator AT may contact the membrane structure 10, but is not limited thereto. As shown in Figure 1, the actuator AT may be distinguished as actuator AT1 disposed on the flap 101 and actuator AT2 disposed on the flap 103.

[0026] The actuator AT has a monotonic electromechanical conversion function for the movement of the membrane structure 10 in the Z direction. In some embodiments, the actuator AT may include a piezoelectric actuator, an electrostatic actuator, a nanoscopic-electrostatic-drive (NED) actuator, an electromagnetic actuator, or any other suitable actuator, but is not limited thereto. For example, in one embodiment, the actuator AT may include a piezoelectric actuator, which may include, for example, two electrodes and a piezoelectric material layer (e.g., lead zirconate titanate, PZT) disposed between the two electrodes, wherein the piezoelectric material layer can actuate the membrane structure 10 according to a drive signal received by the electrodes (e.g., a drive voltage and / or a drive voltage difference between the two electrodes), but is not limited thereto. For example, in another embodiment, the actuator AT may include an electromagnetic actuator (e.g., a planar coil) that actuates the membrane structure 10 based on a received drive signal (e.g., drive current) and a magnetic field (i.e., the membrane structure 10 may be actuated by electromagnetic force), but is not limited thereto. For example, in another embodiment, the actuator AT may include an electrostatic actuator (e.g., a conductive plate) or a NED actuator that actuates the membrane structure 10 based on a received drive signal (e.g., drive voltage) and an electric field (i.e., the membrane structure 10 may be actuated by electrostatic force), but is not limited thereto. Hereinafter, the actuator AT may be exemplified as a piezoelectric actuator.

[0027] For example, if the air pump AFC is a MEMS chip, the membrane structure 10, the anchoring structure AR, and the actuator AT can be MEMS structures within the MEMS chip, but are not limited thereto. In addition, since the air pump AFC can generate airflow and / or air pulses by actuating the membrane structure 10 with the actuator AT, the air pump AFC can be a bladeless fan, but is not limited thereto.

[0028] In this invention, the membrane structure 10 (leaflets 101, 103) can be moved upward or downward by actuation / control of the actuator AT, causing the ventilation opening OPV associated with the slit SL to be formed / opened or closed (i.e., the membrane structure 10 is used to form / open the ventilation opening OPV or close the ventilation opening OPV), wherein the ventilation opening OPV is formed between two opposite sidewalls of the slit SL (i.e., the ventilation opening OPV is formed between the two leaflets 101, leaflets 103). In other words, the ventilation opening OPV is formed because of the slit SL. In the case of "ventilation opening OPV closed / sealed", air has difficulty passing through the space between the two opposite sidewalls of the slit SL, which means that the flow resistance of the ventilation opening OPV is large or greater than a threshold. In the case of "ventilation opening OPV formed / opened", air can easily pass through the space between the two opposite sidewalls of the slit SL, which means that the flow resistance of the ventilation opening OPV is small or less than another threshold.

[0029] In this invention, the air pump AFC can generate airflow and / or air pulses through any suitable airflow generation method. For example, the airflow generation method related to Figures 1 and 2 will be described below, and this airflow generation method can generate airflow and / or air pulses by changing the state of the vent opening OPV and the air pressure on both opposite sides of the membrane structure 10.

[0030] As shown in Figure 1, in the intermediate state S1 of the air pump AFC, the membrane structure 10 (lobe pair) can be actuated and maintained in a substantially horizontal (cross-sectional) first position to temporarily close (or even temporarily seal) the vent opening OPV, making it difficult for air to pass through the space between the two opposite sidewalls of the slit SL. In Figure 1, the two opposite sidewalls of the slit SL (i.e., the first free edge 101n1 of the lobe 101 and the second free edge 103n1 of the lobe 103) partially or completely overlap each other in the horizontal direction (as shown in the gap GP of the slit SL in Figure 1), so that the vent opening OPV is closed and has greater flow resistance. In one embodiment, the horizontal direction is generally referred to as a direction parallel to the horizontal plane, such as the direction X and direction Y perpendicular to the direction Z.

[0031] In Figure 1, since the size of the gap GP (or the width of the slit SL) should be small enough, the airflow through the gap GP (i.e., the narrow channel) can be highly damped due to the viscous forces / resistance of the wall along the airflow path (which can be called the intra-field boundary layer effect in fluid dynamics). Therefore, in intermediate state S1, the airflow through the gap GP is small enough to be negligible. In other words, when the air pump AFC is in intermediate state S1, the vent opening OPV is closed or even sealed. The size of the gap GP (or the width of the slit SL) can be designed according to requirements. For example, the size of the gap GP (or the width of the slit SL) can be less than or equal to 5 micrometers (μm), less than or equal to 3 micrometers, less than or equal to 2 micrometers, or 1 to 2 micrometers, but is not limited thereto. It should be noted that the size of the vent opening OPV in intermediate state S1 can be equivalent to the size of the gap GP.

[0032] In Figure 2, the membrane structure 10 (lobe pair) can be actuated to perform a common-mode motion S2, such that both lobes 101 and 103 are simultaneously actuated in the same direction. For example, both lobes 101 and 103 can be simultaneously actuated to move upward or downward along direction Z. For example, at the end of the common-mode motion S2, the distance between lobe 101 and the first position is the same as the distance between lobe 103 and the first position.

[0033] As shown in Figure 2, when the membrane structure 10 (lobe pair) is actuated to perform common-mode motion S2, the vent opening OPV can be temporarily closed (or even temporarily sealed), making it difficult for air to pass through the space between the two opposite sidewalls of the slit SL. In Figure 2, the two opposite sidewalls of the slit SL (i.e., the first free edge 101n1 of the lobe 101 and the second free edge 103n1 of the lobe 103) partially or completely overlap each other in the horizontal direction, so that the vent opening OPV is closed and has greater flow resistance.

[0034] When the membrane structure 10 (lobe pair) is actuated to perform common-mode motion S2, the air pressure on the two opposite sides of the membrane structure 10 will be different due to the large flow resistance caused by the temporary closure of the vent opening OPV. In other words, the membrane structure 10 (lobe pair) performs common-mode motion S2 to create air pressure change.

[0035] In Figure 2, the membrane structure 10 (lobe pair) can be actuated to perform differential mode motion S3, such that the two lobes 101 and 103 are simultaneously actuated in opposite directions. For example, lobe 101 can be actuated to move downward and lobe 103 can be actuated to move upward (as shown in Figure 2), or lobe 101 can be actuated to move upward and lobe 103 can be actuated to move downward. For example, at the end of differential mode motion S3, the distance between lobe 101 and the first position is the same as the distance between lobe 103 and the first position.

[0036] As shown in Figure 2, when the membrane structure 10 (lobe pair) is actuated to perform differential mode motion S3, the vent opening OPV can be temporarily opened, allowing air to easily pass through the space between the two opposite sidewalls of the slit SL. In Figure 2, the two opposite sidewalls of the slit SL (i.e., the first free edge 101n1 of the lobe 101 and the second free edge 103n1 of the lobe 103) do not overlap each other in the horizontal direction, so that the vent opening OPV opens with less flow resistance.

[0037] When the membrane structure 10 (lobe pair) is actuated to perform differential motion S3, if a pressure difference exists between the two opposite sides of the membrane structure 10, air will naturally flow through the ventilation opening OPV based on this pressure difference and the small flow resistance of the ventilation opening OPV, so that airflow and / or air pulses can be generated.

[0038] Accordingly, the airflow generation method of this embodiment can generate airflow and / or air pulses by actuating the membrane structure 10 (lobe pair) to perform common-mode motion S2 and differential-mode motion S3. For example, a time period of the airflow generation method of this embodiment may include four steps, but is not limited thereto. The first step of the airflow generation method can actuate the membrane structure 10 (lobe pair) to perform common-mode motion S2 so that a pressure difference exists between the two opposite sides of the membrane structure 10. The second step of the airflow generation method can actuate the membrane structure 10 (lobe pair) to return to the intermediate state S1. The third step of the airflow generation method can actuate the membrane structure 10 (lobe pair) to perform differential-mode motion S3 so that air flows naturally through the ventilation opening OPV based on this pressure difference and the small flow resistance of the ventilation opening OPV, thereby generating airflow and / or air pulses. The fourth step of the airflow generation method can actuate the membrane structure 10 (lobe pair) to return to the intermediate state S1. By repeating the time period of the airflow generation method of this embodiment, air pulses can be continuously generated to form airflow.

[0039] The frequency of the aforementioned time period can be designed based on the pulse rate of the air pulse, wherein the frequency of the time period can be synchronized with the pulse rate of the air pulse. In this invention, synchronization of one frequency / ratio with another frequency / ratio generally means that this frequency / ratio is another frequency / ratio multiplied by a rational number (i.e., N / M, where N and M represent integers). In some embodiments, the frequency of this time period can be the same as the pulse rate of the air pulse. In some embodiments, the membrane structure 10 (lobe pair) performs common-mode motion S2 to form a pressure change at a pressure change frequency synchronized with the frequency of this time period, and the membrane structure 10 (lobe pair) performs differential-mode motion S3 to form an opening OPV at an opening frequency synchronized with the frequency of this time period and the pressure change frequency. For example, the frequency of this time period, the pulse rate of the air pulse, the pressure change frequency, and the opening frequency can be the same as each other. For example, if the air pump AFC generates an air pulse at an ultrasonic frequency, the pressure change frequency and the opening frequency are synchronized with this ultrasonic frequency.

[0040] The direction of airflow and the direction of air pulse flow can be determined by the direction of the common-mode motion S2 performed by the membrane structure 10 (lobe pair). When the membrane structure 10 (lobe pair) is actuated to move upward (or downward) to perform only one type of common-mode motion S2 in the first step of multiple time periods, the type of air pressure difference in the first step of these time periods is the same, thus making the flow direction of the air pulse generated in these time periods (third step) the same. Therefore, the air pump AFC can generate single-ended (SE) air pulses or quasi-single-ended air pulses. Furthermore, the air pulses are asymmetrical.

[0041] In this invention, the waveform of a single-ended air pulse or a waveform similar to a single-ended air pulse can refer to a waveform that is (substantially) unipolar with respect to a certain level. For example, a single-ended air pulse or a waveform similar to a single-ended air pulse can refer to a waveform that is (substantially) unipolar with respect to ambient pressure (e.g., 1 ATM). In other words, a single-ended air pulse or a waveform similar to a single-ended air pulse constitutes a clean air movement or clean airflow in a single direction.

[0042] The airflow generation method of the present invention is not limited to the above description. During a time period of the airflow generation method, the number of steps and the sequence of actuation movements of the membrane structure 10 (lobe pair) can be designed according to requirements.

[0043] In another viewpoint, for any common-mode motion S2 of the flap pair, a pair of acoustic pressure waves are generated, one in the space on one side of the membrane structure 10 and the other in the space on the opposite side of the membrane structure 10, and these two acoustic pressure waves have the same amplitude but opposite polarities. Therefore, when the vent opening OPV is opened, the pressure difference between the two air volumes near the vent opening OPV will neutralize each other. Accordingly, when the timing of the differential-mode motion S3 reaching its peak (i.e., the timing of the vent opening OPV reaching its maximum opening) aligns with the timing of the acceleration of the common-mode motion S2 reaching its peak, it is expected that the acoustic pressure generated by the common-mode motion S2 should be suppressed or eliminated by the opening of the vent opening OPV, resulting in automatic neutralization between the two acoustic pressures on the two opposite sides of the membrane structure 10, where these two acoustic pressures have the same magnitude but opposite polarities. This means that when the vent opening OPV is open, the air pump AFC will generate (near) net zero air pressure. Therefore, when the opening time of the vent opening OPV overlaps with the time of one of the two polarities of the acceleration of the common mode motion S2 of the flap pair, the air pump AFC will generate a single-ended air pulse or a quasi-single-ended air pulse.

[0044] In addition, by aligning the opening timing of the ventilation opening OPV with the acceleration timing of the common-mode motion S2 of the flap pair, the air pump AFC can generate asymmetrical air pulses.

[0045] In some embodiments, the membrane structure 10 (lobe pair) may be actuated to simultaneously perform common-mode motion S2 and differential-mode motion S3, but is not limited thereto. In some embodiments, the membrane structure 10 may include other portions such that the common-mode motion S2 and differential-mode motion S3 are simultaneously performed by the membrane structure 10, but is not limited thereto.

[0046] In this invention, the actuator AT can receive any suitable signal to actuate the membrane structure 10. In some embodiments, the membrane structure 10 is actuated by a modulation drive signal SM to perform a common-mode motion S2 to form a pressure change, and the membrane structure 10 is actuated by a demodulation drive signal SV to perform a differential-mode motion S3 to form a ventilation opening OPV, wherein both the modulation drive signal SM and the demodulation drive signal SV are related to the output amplitude of the air pulse. It should be noted that the demodulation drive signal SV can be presented as +SV or –SV in Figure 4 to represent opposite signals.

[0047] In addition, the modulation frequency of the modulation drive signal SM and the demodulation frequency of the demodulation drive signal SV can be correlated with the pulse rate of the air pulse. For example, the modulation frequency and the demodulation frequency can be synchronized with the pulse rate of the air pulse, such that the modulation frequency and the demodulation frequency can be synchronized with the pressure change frequency of the air pressure change, the opening frequency of the ventilation opening OPV, and the frequency of the aforementioned time period, but are not limited thereto.

[0048] In some embodiments, the actuator AT may receive the modulation drive signal SM and the demodulation drive signal SV at different times, but this is not a limitation. In some embodiments, the actuator AT may include multiple sub-sections in top view, one sub-section may receive the modulation drive signal SM, and another sub-section may receive the demodulation drive signal SV, but this is not a limitation. In some embodiments, the actuator AT may include a first electrode and a second electrode, the first electrode may receive the modulation drive signal SM, and the second electrode may receive the demodulation drive signal SV, but this is not a limitation.

[0049] Furthermore, by controlling the modulation drive signal SM and / or demodulation drive signal SV, the flow direction of the airflow (air pulse) generated by the air pump AFC can be reversible. For details, please refer to U.S. Patent Application No. 18 / 624,105 filed by the same applicant; for the sake of brevity, it will not be described here.

[0050] Details (e.g., structure, drive signals, and motion) of airflow generating MEMS devices (i.e., air pumps AFC) manufactured using semiconductor processes, as well as their design / operating principles, can be found in U.S. Patent No. 11,943,585, U.S. Patent Application No. 18 / 321,757, and U.S. Patent Application No. 18 / 624,105 filed by the same applicant. These U.S. patents and U.S. patent applications are therefore incorporated herein by reference.

[0051] As mentioned above, the air pump AFC of the present invention can generate asymmetrical air pulses and can be applied to applications such as cooling, drying, dehumidification, heat dissipation, ventilation, air sampling, air extraction and / or exhaust, wherein (asymmetrical) air pulses are generated to form a continuous unidirectional clean air movement.

[0052] Furthermore, the air pump AFC of the present invention is used in airflow applications and can be installed within an air quality sensing device, which is used to sense the concentration of specific particles (e.g., particulate matter, such as PM 2.5 or PM 10) or compounds (e.g., ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO)) in the air. Therefore, the size of the air quality sensing device can be significantly reduced.

[0053] For example, Figure 3 shows a schematic diagram of an air pulse AP according to an embodiment of the present invention. The air pulse can be generated by an air pump AFC of the present invention, and the air pump AFC includes a membrane structure 10. As described above, the membrane structure 10 of the air pump AFC can be actuated to perform motion, generating an air pulse AP at an ultrasonic frequency fpulse (e.g., 96 kHz or 192 kHz), the ultrasonic frequency fpulse being, for example, the reciprocal of the operating period TCY of the ultrasonic carrier frequency fUC. In this case, the ultrasonic frequency fpulse can be the ultrasonic carrier frequency fUC. The air pulse AP can generate a net airflow in a single direction.

[0054] In one embodiment, the first air pulse AP1 can generate a first net airflow that is continuously directed in a single direction (e.g., first direction D1). Taking Figure 3 as an example, during a first time period T1, all air pulses AP are directed towards the first direction D1. When the first time period T1 is at least equal to or longer than the reciprocal of the minimum audible frequency for humans, the first net airflow generated by the first air pulse AP1 can be considered to be continuously directed in a single direction (e.g., first direction D1). For example, when the minimum audible frequency for humans is 10 Hz, when the first time period T1 is at least equal to or longer than 0.1 seconds, the first net airflow can be considered to be continuously directed in a single direction (e.g., first direction D1). It should be noted that the first amplitudes of the first air pulses AP1 corresponding to the first direction D1 can be the same or different from each other.

[0055] On the other hand, the air pump AFC can generate a second air pulse AP2, which can generate a second net airflow continuously directed toward a second direction D2, wherein the second direction D2 is opposite to the first direction D1. In one embodiment, when the air pump AFC generates significant airflow or air movement, and the air pulse switching between the first direction D1 and the second direction D2 is indistinguishable, the first net airflow during the first time period T1 can be considered as continuously directed toward the first direction D1, and / or the second net airflow during the second time period T2 can be considered as continuously directed toward the second direction D2.

[0056] The membrane structure can be actuated by a demodulation drive signal SV and a modulation drive signal SM. It should be noted that, in this invention, the modulation drive signal SM can also be called a modulation signal, which is also a type of drive signal. Similarly, the demodulation drive signal SV can be called a demodulation signal, which is also a type of drive signal.

[0057] Figure 4 is a schematic diagram of the waveforms of the demodulated signal and the modulated signal according to an embodiment of the present invention, wherein the transition between high and low voltages is ignored. As shown in Figure 4, the modulation / drive signal (e.g., modulation drive signal SM) can be generated based on the input signal (e.g., input audio signal SIN), and the input signal can be or include a DC offset (or a non-zero DC offset) (e.g., DC voltage or non-zero DC voltage). In other words, the input signal can be only a DC signal, but is not limited thereto.

[0058] In one embodiment, the DC offset may be related to the direction of the net airflow. For example, during a first time period T1, in response to a positive DC offset, an air pulse may generate a first net airflow continuously directed toward a first direction D1. On the other hand, during a second time period T2, in response to a negative DC offset, an air pulse generated by the air pump AFC may generate a second net airflow continuously directed toward a second direction D2, which is opposite to the first direction D1. In this regard, the air pump AFC or airflow generating device of the present invention can be considered as a voltage-to-airflow converter that can convert voltage into airflow.

[0059] In addition to the polarity of the DC offset, the direction of the net airflow can also be determined or controlled by the phase between the modulation signal (modulation drive signal SM) and the demodulation signal (demodulation drive signal SV). For example, in Figure 4, the transition state of the demodulation signal (demodulation drive signal SV) aligns with the period when the modulation signal (modulation drive signal SM) is at a low level. In this case, the air pump AFC can generate airflow, for example, toward a third direction. When the demodulation signal (demodulation drive signal SV) or its phase is shifted such that the transition state of the demodulation signal (demodulation drive signal SV) aligns with the period when the modulation signal (demodulation drive signal SM) is at a high level, the air pump AFC can generate airflow toward a fourth direction, which is opposite to the third direction. In short, the direction of the net airflow generated by the air pump AFC can be determined or controlled by the phase (or phase difference) between the modulation signal (modulation drive signal SM) and the demodulation signal (demodulation drive signal SV).

[0060] The intensity or volume of the net airflow can be a function of the DC offset or related to the magnitude of the DC offset. By maintaining the airflow direction (whether a first direction or a second direction), the air pump AFC can dissipate heat, dehumidify, ventilate, sample air, extract air, exhaust air, and / or promote air circulation. In this case, the air pump AFC can be considered a fanless blower or a bladeless fan. That is, the air pump AFC can also be considered a fanless blower, especially when the drive signal or modulated drive signal applied to it is based on an input signal that contains a non-zero DC offset / component. In this invention, the terms "air pulse generating device," "airflow generating device," "air pump," and "blower" are used interchangeably.

[0061] The small size of the air pump of the present invention enables an air quality sensing module including the air pump to be installed (integrated) in a handheld device. For example, the handheld device may be a (smart) phone, a (smart) watch, or other suitable handheld device.

[0062] Please refer to Figure 5, which is a cross-sectional schematic diagram of an air quality sensing module according to an embodiment of the present invention. As shown in Figure 5, the air quality sensing module 26A includes a housing HSS, and a cavity CB exists within the housing HSS. The housing HSS may be a one-piece structure or may be formed by multiple substructures.

[0063] As shown in Figure 5, the air quality sensing module 26A includes an air quality sensor AQ, which is disposed within the housing HSS. The air quality sensor AQ performs an air quality sensing operation to sense at least one target DTT, thereby sensing the air quality in the cavity CB. For example, the air quality sensor AQ can sense the concentration of the target DTT, which may include, but is not limited to, specific particles (e.g., PM 2.5 or PM 10) or compounds (e.g., ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide) in the air.

[0064] As shown in Figure 5, the air quality sensing module 26A includes an air pump Q00, which is any of the aforementioned air pumps AFC, wherein the air pump Q00 generates airflow toward or away from the cavity CB to enable the air quality sensor AQ to perform air quality sensing operations. For example, the air pump Q00 may be disposed in a hole H1 corresponding to the housing HSS, such that the air pump Q00 can generate airflow from the surrounding environment toward the cavity CB or generate airflow from the cavity CB toward the surrounding environment.

[0065] The direction of airflow can be designed according to the type of air quality sensing module 26A or other requirements. For example (as shown in Figure 5), air pump Q00 generates a first airflow from the surrounding environment toward cavity CB, allowing air quality sensor AQ to sense the air quality of the surrounding environment in the first time period; air pump Q00 generates a second airflow from cavity CB toward the surrounding environment to update cavity CB in the second time period (i.e., the direction of airflow generated by air pump Q00 of the present invention is reversible). In other words, air pump Q00 draws air into and extracts air from cavity CB at different time periods. It should be noted that the pressure of cavity CB in the first time period may be greater than the pressure of cavity CB in the second time period. For example, the pressure of cavity CB in the first time period may be greater than the pressure of the surrounding environment, but this is not a limitation.

[0066] As mentioned above, the direction of airflow can be reversed by changing the phase (or phase difference) between the modulation signal (modulation drive signal SM) and the demodulation signal (demodulation drive signal SV), or by changing the DC offset embedded in the input signal (e.g., input audio signal SIN).

[0067] Furthermore, the intensity of the airflow generated by the air pump Q00 of the present invention is adjustable. For example, the intensity of the airflow can be adjusted by adjusting the amplitude of the modulation signal (modulation drive signal SM) or the amplitude of the demodulation signal (demodulation drive signal SV). For example, the intensity of the airflow can also be adjusted by adjusting the frequency of the modulation signal (modulation drive signal SM) or the frequency of the demodulation signal (demodulation drive signal SV), which utilizes the resonant gain of the membrane structure 10 (e.g., a pair of lobes), especially when the frequency of the modulation signal (modulation drive signal SM) or the frequency of the demodulation signal (demodulation drive signal SV) is close to the resonant frequency of the membrane structure 10.

[0068] Please refer to Figure 6, which is a cross-sectional schematic diagram of an air quality sensing module according to an embodiment of the present invention. As shown in Figure 6, another type of air quality sensing module 27A is provided. In Figure 6, the air quality sensing module 27A may include another air pump Q01, disposed in or corresponding to the hole H2 of the housing HSS, wherein the structure of the air pump Q01 may be the same as or different from the structure of the air pump Q00. In the present invention, the direction of the airflow generated by the air pumps Q00 and Q01 can be designed according to requirements. In one example, in a first time period, the air pump Q00 may generate a first airflow from the surrounding environment toward the cavity CB, and the air pump Q01 may generate a third airflow from the surrounding environment toward the cavity CB; in a second time period, the air pump Q00 may generate a second airflow from the cavity CB toward the surrounding environment, and the air pump Q01 may generate a fourth airflow from the cavity CB toward the surrounding environment, but this is not a limitation. It should be noted that the pressure of the cavity CB in the first time period may be greater than the pressure of the cavity CB in the second time period.

[0069] In another example, air pump Q00 can generate airflow from the surrounding environment toward cavity CB, and air pump Q01 can simultaneously generate another airflow from cavity CB toward the surrounding environment, or air pump Q00 can generate airflow from cavity CB toward the surrounding environment, and air pump Q01 can simultaneously generate another airflow from the surrounding environment toward cavity CB (i.e., the direction of the airflow generated by air pumps Q00 and Q01 of the present invention is reversible), such that cavity CB can be an air passage, but is not limited thereto.

[0070] Furthermore, the air pump of the present invention can be integrated into a packaged air quality sensing module, wherein embodiments of the packaged air quality sensing module are illustrated in Figures 7 to 9. It should be noted that the packaged air quality sensing module can be formed by a semiconductor process (a semiconductor process includes a packaging process).

[0071] In Figure 7, the housing HSS of the air quality sensing module 28A may include a substrate BS, wherein the air pump Q00 and the air quality sensor AQ may be disposed on the substrate BS. The substrate BS may be a rigid substrate or a flexible substrate, wherein the substrate BS may include glass, plastic, quartz, sapphire, metal, polymer (e.g., polyimide (PI), polyethylene terephthalate (PET)), any suitable material or combination thereof. In one example, the substrate may be a circuit board including, but not limited to, laminates (e.g., copper clad laminate (CCL)), land grid array boards (LGA boards), or any other suitable board containing conductive material. In Figure 7, the normal direction of the substrate BS may be parallel to the Z direction.

[0072] In Figure 7, the housing HSS of the air quality sensing module 28A may include a cover structure CV for covering and protecting the air pump Q00 and the air quality sensor AQ. In Figure 7, the air pump Q00 and the air quality sensor AQ may be disposed between the substrate BS and the cover structure CV. For example, the cover structure CV may include glass, plastic, quartz, sapphire, metal, polymer, any suitable material or combination thereof. For example, the cover structure CV may be a monolithic structure or may be formed from multiple substructures (e.g., multiple substrates).

[0073] In Figure 7, the substrate BS may have a hole H1, and the air pump Q00 corresponds to the hole H1, such that the air pump Q00 can generate airflow from the surrounding environment toward the cavity CB or from the cavity CB toward the surrounding environment. For example, in Figure 7, the air pump Q00 generates a first airflow from the surrounding environment toward the cavity CB, such that the air quality sensor AQ senses the air quality of the surrounding environment in a first time period; the air pump Q00 generates a second airflow from the cavity CB toward the surrounding environment to update the cavity CB in a second time period. It should be noted that the pressure of the cavity CB in the first time period may be greater than the pressure of the cavity CB in the second time period.

[0074] Compared to the air quality sensing module 28A shown in Figure 7, the covering structure CV of the air quality sensing module 29A shown in Figure 8 may also have another hole H2, allowing the airflow generated by the air pump Q00 to flow between the two holes H1 and H2, while the cavity CB can serve as an air passage. Since the direction of the airflow generated by the air pump Q00 of the present invention is reversible, the air pump Q00 can generate airflow from the surrounding environment toward the cavity CB at one time and airflow from the cavity CB toward the surrounding environment at another time, but is not limited thereto.

[0075] Compared to the air quality sensing module 28A shown in Figure 7, the air quality sensing module 30A shown in Figure 9 may have another air pump Q01, and the substrate BS may also have a hole H2. In one example (Figure 9), during a first time period, air pump Q00 may generate a first airflow from the surrounding environment toward the cavity CB, and air pump Q01 may generate a third airflow from the surrounding environment toward the cavity CB; during a second time period, air pump Q00 may generate a second airflow from the cavity CB toward the surrounding environment, and air pump Q01 may generate a fourth airflow from the cavity CB toward the surrounding environment, such that the pressure of the cavity CB during the first time period may be greater than the pressure of the cavity CB during the second time period, but is not limited thereto.

[0076] In another example (Figure 9), air pump Q00 can generate airflow from the surrounding environment toward cavity CB, and air pump Q01 can simultaneously generate another airflow from cavity CB toward the surrounding environment, or air pump Q00 can generate airflow from cavity CB toward the surrounding environment, and air pump Q01 can simultaneously generate another airflow from the surrounding environment toward cavity CB (i.e., the direction of the airflow generated by air pumps Q00 and Q01 of the present invention is reversible), so that cavity CB can be an air passage, but is not limited thereto.

[0077] Figure 10 illustrates three designs for the air quality sensing module. In the first design DS1, the air pump Q00 can draw air into and out of the cavity CB at different times through the hole H1. The air quality sensing module 26A shown in Figure 5 and the air quality sensing module 28A shown in Figure 7 belong to the first design DS1. In the second design DS2, the air pump Q00 can draw air into the cavity CB through the hole H1 and the air can flow out of the cavity CB through the hole H2, or the air pump Q00 can draw air out of the cavity CB through the hole H1 and the air can flow into the cavity CB through the hole H2. The air quality sensing module 29A shown in Figure 8 belongs to the second design DS2. In the third design DS3, air pumps Q00 and Q01 can simultaneously draw air into the cavity CB or simultaneously draw air out of the cavity CB through holes H1 and H2. Alternatively, air pump Q00 can draw air into the cavity CB through hole H1 and air pump Q01 can simultaneously draw air out of the cavity CB through hole H2. The air quality sensing module 27A shown in Figure 6 and the air quality sensing module 30A shown in Figure 9 belong to the third design DS3.

[0078] Please refer to Figure 11, which is a schematic diagram of an air pump according to an embodiment of the present invention. It should be noted that the air pump Q00 shown in Figure 11 can be an example used in an air quality sensing module, and the air pump Q00 can be exemplified as a MEMS chip. As shown in Figure 11, the two lobes 101 and 103 of the air pump Q00 are opposite each other in a top view along the top view direction (i.e., direction Z), and actuators AT1 and AT2 are respectively disposed on the lobes 101 and 103. It should be noted that the two lobes 101 and 103 form a lobe pair.

[0079] In Figure 11, the petal 101 includes a first anchoring edge 101r, which is anchored to the anchoring structure AR. The petal 101 also includes a non-anchored first free edge 101n, in addition to the first anchoring edge 101r. Similarly, the petal 103 includes a second anchoring edge 103r, which is anchored to the anchoring structure AR. The petal 103 also includes a non-anchored second free edge 103n, in addition to the second anchoring edge 103r. In other words, each petal 101, 103 has only one anchoring edge, while the other edges are free edges.

[0080] In Figure 11, a slit SL is formed between two lobes 101 and 103, such that the two lobes 101 and 103 are separated by the slit SL, and a first free edge 101n1 of the lobe 101 and a second free edge 103n1 of the lobe 103 are defined by the slit SL (the first free edge 101n1 and the second free edge 103n1 are the two opposite sidewalls of the slit SL). It should be noted that the ventilation opening OPV formed between the two lobes 101 and 103 is formed because of the slit SL.

[0081] Simulations were conducted to verify the effectiveness of the air pump or airflow generating element / chip, which generates airflow toward a closed cavity. Simulation results showed that the air pressure inside the cavity could rise to a steady state in less than 0.5 milliseconds (ms). This means that, based on measurement results, the air quality sensing module does not require a long time to acquire air quality data; therefore, in addition to sensing air quality at close range, it can also achieve real-time air quality sensing.

[0082] In summary, by applying a small-sized air pump or airflow generating chip to the air quality sensing module, the air quality sensing module can be integrated into handheld electronic devices (such as smartphones or smartwatches). Therefore, revolutionary real-time, near-field air quality sensing is achievable. The above description is merely a preferred embodiment of the present invention, and all equivalent variations and modifications made within the scope of the claims of this invention should be considered within the scope of this invention. [Simplified Explanation of the Diagram]

[0013] Figure 1 is a cross-sectional schematic diagram of an air pump according to an embodiment of the present invention. Figure 2 is a cross-sectional schematic diagram of the common mode movement and differential mode movement of the air pump according to an embodiment of the present invention. Figure 3 is a schematic diagram of an air pulse according to an embodiment of the present invention. Figure 4 is a schematic diagram of the waveforms of the demodulation signal and the modulation signal according to an embodiment of the present invention. Figure 5 is a cross-sectional schematic diagram of an air quality sensing module according to an embodiment of the present invention. Figure 6 is a cross-sectional schematic diagram of an air quality sensing module according to an embodiment of the present invention. Figure 7 is a cross-sectional schematic diagram of an air quality sensing module according to an embodiment of the present invention. Figure 8 is a cross-sectional schematic diagram of an air quality sensing module according to an embodiment of the present invention. Figure 9 is a cross-sectional schematic diagram of an air quality sensing module according to an embodiment of the present invention. Figure 10 is a schematic diagram of three designs of the air quality sensing module of the present invention. Figure 11 is a schematic diagram of an air pump according to an embodiment of the present invention.

Claims

1. An air pump, comprising: A first lob and a second lob, wherein the first lob and the second lob are opposite each other in a top view along a top view direction; a first actuator disposed on the first lob; a second actuator disposed on the second lob; and an anchoring structure; wherein the first lob includes a first anchoring edge anchored to the anchoring structure, and the first lob includes a plurality of non-anchored first free edges in addition to the first anchoring edge; wherein the second lob includes a second anchoring edge anchored to the anchoring structure, and the second lob includes a plurality of non-anchored second free edges in addition to the second anchoring edge.

2. The air pump as claimed in claim 1, wherein a slit is formed between the first leaflet and the second leaflet; wherein one of the first free edges of the first leaflet relative to the first anchoring edge and one of the second free edges of the second leaflet relative to the second anchoring edge are defined by the slit.

3. The air pump of claim 1, wherein the first and second lobes are actuated to perform a differential motion to form an opening; wherein the opening is formed by a slit.

4. The air pump as claimed in claim 1, wherein the first and second lobes perform a common-mode motion to create a pressure change, and the first and second lobes perform a differential-mode motion to create an opening.

5. The air pump of claim 4, wherein the first and second lobes perform the common-mode motion to form the pressure change at a frequency, and the first and second lobes perform the differential-mode motion to form the opening at an opening frequency synchronized with the frequency.

6. The air pump of claim 1, wherein the first and second flaps are actuated to generate a plurality of air pulses, the air pulses being asymmetrical.

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