Patent Publication Number: US-2021172850-A1

Title: External gas detecting device

Description:
FIELD OF THE INVENTION 
     The present disclosure relates to an external gas detecting device, and more particularly to an external gas detecting device with extremely thin profile. 
     BACKGROUND OF THE INVENTION 
     Suspension particles are solid particles or droplets within the gas. Since the suspension particles are extremely fine, it is often that the suspension particles are inhaled into the lung by passing through the nose hair inside the nasal cavity of human&#39;s body. As a result, inflammation of the lungs, asthma or cardiovascular diseases are caused. Furthermore, if the suspension particles are attached with other pollutants, it will be more harmful to the respiratory system of human&#39;s body. Recently, the problem of the gas pollution is getting worse, especially, the concentration data of fine suspended particles, e.g., PM2.5, is often too high. Therefore, the detection of the concentration of the suspension particles is getting more attention. However, since the gas flows unstably owing to the wind direction and air volume, and the conventional air quality monitoring stations used for detecting the suspension particles are fixedly disposed at certain locations, people cannot check the concentration of the suspension particles in the surrounding environment. 
     Moreover, people pay more attention to the quality of the air around their lives. For example, carbon monoxide, carbon dioxide, volatile organic compounds (VOC), PM2.5, nitric oxide, sulfur monoxide and even the suspended particles contained in the air are exposed in the environment to affect the human health, and even endanger the life seriously. Therefore, the quality of environmental air has attracted the attention of various countries. How to detect the air quality and avoid the harm from the area with poor air quality is a problem that urgently needs to be solved. 
     In order to confirm the quality of the air, it is feasible to use a gas sensor to detect the air surrounding in the environment. If the detection information is provided in real time to warn the people in the environment, it is helpful of avoiding the harm and facilitates the people to escape the hazard immediately. Thus, it prevents the hazardous gas exposed in the environment from affecting the human health and causing the harm. Therefore, it is a very good application to use a gas sensor to detect the air in the surrounding environment. 
     On the other hand, it is common that the portable devices are carried by the modern people when they go out. It is taken seriously that the gas detection module is embedded in the portable device for detecting the air in the surrounding environment. In particular, the current development trend of portable devices is light and thin Therefore, how to make the gas detection module thinner and install it in the portable device is an important subject developed in the present disclosure. There is a need of providing an external gas detecting device with thin profile and easy to be carried, so that the user can detect the concentration of the suspension particles and the air quality in the surrounding environment anytime and anywhere. 
     SUMMARY OF THE INVENTION 
     An object of the present disclosure provides an external gas detecting device. With the gas detection module embedded in the external gas detecting device, the air quality in the surrounding environment around the user is detected anytime, the information of the air quality is transmitted to the external transmission device in real time, and an alarm of the information of the gas detection is obtained. 
     In accordance with an aspect of the present disclosure, an external gas detecting device is provided. The external gas detecting device includes a casing, a gas detection module and an external connector. The gas detection module is disposed in the casing and detects a gas transported into the casing to generate a gas information. The external connector is connected to and disposed on the casing. The external connector is used to be connected to an external power supply so as to enable the gas detection module, and is used to transmit the gas information so as to achieve the outward transmission of the gas information. 
     The above contents of the present disclosure will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  shows a schematic exterior view illustrating an external gas detecting device according to an embodiment of the present disclosure; 
         FIG. 1B  shows a schematic exterior view illustrating a gas detecting and transmitting module of an external gas detecting device according to another embodiment of the present disclosure; 
         FIG. 1C  shows a schematic exterior view illustrating the assembly of a gas detecting and transmitting module and an external connector of an external gas detecting device according to another embodiment of the present disclosure; 
         FIG. 1D  shows a schematic exterior view illustrating the assembly of a gas detecting and transmitting module, an external connector and a casing of an external gas detecting device according to another embodiment of the present disclosure; 
         FIG. 1E  shows a schematic exterior view illustrating an external gas detecting device according to another embodiment of the present disclosure; 
         FIG. 2A  is a schematic exterior view illustrating a gas detection module according to an embodiment of the present disclosure; 
         FIG. 2B  is a schematic exterior view illustrating the gas detection module according to the embodiment of the present disclosure and taken from another perspective angle; 
         FIG. 2C  is a schematic exploded view illustrating the gas detection module of the present disclosure; 
         FIG. 3A  is a schematic perspective view illustrating a base of the gas detection module of the present disclosure; 
         FIG. 3B  is a schematic perspective view illustrating the base of the gas detection module of the present disclosure and taken from another perspective angle; 
         FIG. 4  is a schematic perspective view illustrating a laser component and a particle sensor accommodated in the base of the gas detection module of the present disclosure; 
         FIG. 5A  is a schematic exploded view illustrating the combination of the piezoelectric actuator and the base of the gas detection module of the present disclosure; 
         FIG. 5B  is a schematic perspective view illustrating the combination of the piezoelectric actuator and the base of the gas detection module of the present disclosure; 
         FIG. 6A  is a schematic exploded view illustrating the piezoelectric actuator of the gas detection module of the present disclosure; 
         FIG. 6B  is a schematic exploded view illustrating the piezoelectric actuator of the gas detection module of the present disclosure and taken from another perspective angle; 
         FIG. 7A  is a schematic cross-sectional view illustrating the piezoelectric actuator accommodated in the gas-guiding-component loading region of the gas detection module of the present disclosure; 
         FIGS. 7B and 7C  schematically illustrate the actions of the piezoelectric actuator of  FIG. 7A ; 
         FIGS. 8A to 8C  schematically illustrate gas flowing paths of the gas detection module; 
         FIG. 9  schematically illustrates a light beam path emitted from the laser component of the gas detection module of the present disclosure; 
         FIG. 10A  is a schematic cross-sectional view illustrating a MEMS pump of the gas detection module of the present disclosure; 
         FIG. 10B  is a schematic exploded view illustrating the MEMS pump of the gas detection module of the present disclosure; 
         FIGS. 11A to 11C  schematically illustrate the actions of the MEMS pump of the gas detection module of the present disclosure; and 
         FIG. 12  is a block diagram showing the relationship between the controlling circuit unit and the related arrangement of the external gas detecting device according to the embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present disclosure will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed. 
     Please refer to  FIGS. 1A, 1B, 1C, 1D, 1E, 2A, 2B, 2C and 12 . The present disclosure provides an external gas detecting device  100 . The external gas detecting device  100  includes a casing  10 , a gas detection module  20  and an external connector  30 . The casing  10  includes a gas-inlet channel  10   a  and a gas-outlet channel  10   b . The gas detection module  20  is disposed in the casing  10  and transports the gas outside the casing  10  into the casing  10  through the gas-inlet channel  10   a , so as to output a gas information. After the gas is detected, the gas detection module  20  transports the detected gas out of the casing  10 . The external connector  30  is connected to and disposed on the casing  10 , and is connected to an external power supply so as to enable the gas detection module  20  to operate and achieve the outward transmission of the gas information. The external connector  30  is one selected from the group consisting of a USB connector, a mini USB connector, a Micro USB connector, a USB Type C connector, an AC adapter, a DC power adapter, a power connector, a terminal connector and combination thereof. In the embodiment, as shown in  FIG. 1A , the external connector  30  is combination of an AC adapter  30   a  in a plug form and a USB connector  30   b  in a receptacle form. The AC adapter  30   a  can be plugged in an external receptacle (not shown) and be electrically coupled therewith so as to achieve the connection between the external power supply and the external gas detecting device  100 . Consequently, the gas detection module  20  is enabled to operate, detect the gas and generate the gas information. Thereafter, by connecting the USB connector  30   b  to an external connection device  50 , such as mobile device, the outward transmission of the gas information is achieved. 
     As shown in  FIGS. 1B and 12 , the external gas detecting device  100  further includes a controlling circuit unit  40 . A microprocessor  40   a , a communicator  40   b  and a power module  40   c  are disposed on and electrically coupled with the controlling circuit unit  40 . To make the external gas detecting device  100  meet the trend of lightweight-miniaturized structure and portability, the gas detection module  20  of the present disclosure is assembled with the controlling circuit unit  40  after the thickness thereof is decreased, so as to form a gas detecting and transmitting module  100 A. The gas detecting and transmitting module  100 A has a length L 1  ranging between 35 mm and 55 mm, a width W 1  ranging between 10 mm and 35 mm, and a thickness H 1  ranging between 1 mm and 7.5 mm. The sizes of the gas detecting and transmitting module  100 A benefits the assembly shown in  FIG. 1B . Thereafter, as shown in  FIG. 1C , the gas detecting and transmitting module  100 A is further assembled with and electrically connected to the external connector  30 . The casing  10  covers the gas detecting and transmitting module  100 A and the external connector  30  so as to protect them, and the external connector  30  is exposed to achieve the electrical connection, as shown in  FIG. 1D . In addition, the casing  10  includes the gas-inlet channel  10   a  and the gas-outlet channel  10   b . Therefore, as shown in  FIG. 12 , the power module  40   c  can receive an electric energy through a power supply device  70  via a wireless transmission technology for storing the electric energy. The microprocessor  40   a  enables the gas detection module  20  to detect and operate by controlling a driving signal of the gas detection module  20 . The gas detection module  20  is disposed in the casing  10  so as to transport the gas into the interior of the casing  10  through the gas-inlet channel  10   a  and obtain the gas information, and then transport the detected gas out of the casing  10  through the gas-outlet channel  10   b . The microprocessor  40   a  converts the gas information of the gas detection module  20  into a detection data. The communicator  40   b  is used to receive the detection data outputted by the microprocessor  40   a , so that the detection data is externally transmitted to an external transmission device  60  through the communication transmission for storing. Furthermore, it results that the external transmission device  60  generates a gas detection information and an alarm based on the detection data. In other embodiments, the external connector  30  is connected to the external connection device  50 , such as mobile device, to achieve the connection between the external power supply and the external gas detecting device  100  and enable the gas detection module  20  to operate. The gas detection module  20  detects the gas outside the casing  10  to generate the gas information. The microprocessor  40   a  converts the gas information of the gas detection module  20  to a detection data for storing. By the connection between the external connector  30  and the external connection device  50 , the detection data is transmitted to the external connection device  50  for processing and application. Furthermore, the gas detection data is further transmitted outwardly by the external connection device  50  through the communication transmission to the external transmission device  60  for storing. Furthermore, it results that the external transmission device  60  generates the gas detection information and the alarm based on the detection data. 
     Preferably but not exclusively, the above-mentioned external transmission device  60  is one selected from the group consisting of a cloud system, a portable device and a computer system. Preferably but not exclusively, the above-mentioned communication transmission is the wired communication transmission, such as USB transmission. Preferably but not exclusively, the communication transmission is the wireless communication transmission, such as Wi-Fi transmission, Bluetooth transmission, a radio frequency identification transmission or a near field communication transmission. The external gas detecting device  100  including the above-mentioned features has a length L ranging between 45 mm and 70 mm, a width W ranging between 25 mm and 42 mm, and a thickness H ranging between 7 mm and 13 mm. It benefits the construction as shown in  FIGS. 1A, 1B, 1C, 1D and 1E  which meet the requirement of the design with lightweight-miniaturized structure and portability. 
     Please refer to  FIGS. 2A to 2C . The present disclosure provides a gas detection module  20  including a base  1 , a piezoelectric actuator  2 , a driving circuit board  3 , a laser component  4 , a particle sensor  5  and an outer cover  6 . In the embodiment, the driving circuit board  3  covers and is attached to the second surface  12  of the base  1 , and the laser component  4  is positioned and disposed on the driving circuit board  3 , and is electrically connected to the driving circuit board  3 . The particle sensor  5  is positioned and disposed on the driving circuit board  3 , and is electrically connected to the driving circuit board  3 . The outer cover  6  covers the base  1  and is attached to the first surface  11  of the base  1 . Moreover, the outer cover  6  includes a side plate  61 . The side plate  61  includes an inlet opening  61   a  and an outlet opening  61   b . When the gas detection module  20  is disposed in the casing  10 , the inlet opening  61   a  is spatially corresponding to the gas-inlet channel  10   a  of the casing  10 , and the outlet opening  61   b  is spatially corresponding to the gas-outlet channel  10   b  of the casing  10 . 
     Please refer to  FIG. 3A  and  FIG. 3B . In the embodiment, the base  1  includes a first surface  11 , a second surface  12 , a laser loading region  13 , a gas-inlet groove  14 , a gas-guiding-component loading region  15  and a gas-outlet groove  16 . The first surface  11  and the second surface  12  are two opposite surfaces. The laser loading region  13  is hollowed out from the first surface  11  to the second surface  12 . The gas-inlet groove  14  is concavely formed from the second surface  12  and disposed adjacent to the laser loading region  13 . The gas-inlet groove  14  includes a gas-inlet  14   a  and two lateral walls. The gas-inlet  14   a  is in fluid communication with an exterior of the base  1  and spatially corresponds to the inlet opening  61   a  of the outer cover  6 . The two lateral walls are extended towards a transparent window  14   b  corresponding to the laser loading region  13 . In that, the first surface  11  of the base  1  is attached and covered by the outer cover  6 , and the second surface  12  of the base  1  is attached and covered by the driving circuit board  3 , so that an inlet path is collaboratively defined by the gas-inlet groove  14  and the driving circuit board  3 . 
     In the embodiment, the gas-guiding-component loading region  15  mentioned above is concavely formed from the second surface  12  and in fluid communication with the gas-inlet groove  14 . A ventilation hole  15   a  is penetrated through a bottom surface of the gas-guiding-component loading region  15 . The gas-outlet groove  16  mentioned above includes a gas-outlet  16   a , and the gas-outlet  16   a  spatially corresponds to the outlet opening  61   b  of the outer cover  6 . The gas-outlet groove  16  includes a first section  16   b  and a second section  16   c . The first section  16   b  is hollowed out from the first surface  11  to the second surface  12  in a vertical projection area of the gas-guiding-component loading region  15  spatially corresponding thereto. The second section  16   c  is hollowed out from the first surface  11  to the second surface  12  in a region of the first surface  11  misaligned to the vertical projection area of the gas-guiding-component loading region  15  and extended therefrom. The first section  16   b  and the second section  16   c  are connected to form a stepped structure. Moreover, the first section  16   b  of the gas-outlet groove  16  is in fluid communication with the ventilation hole  15   a  of the gas-guiding-component loading region  15 , and the second section  16   c  of the gas-outlet groove  16  is in fluid communication with the gas-outlet  16   a . In that, the first surface  11  of the base  1  is attached and covered by the outer cover  6 , and the second surface  12  of the base  1  is attached and covered by the driving circuit board  3 , so that an outlet path is collaboratively defined by the gas-outlet groove  16 , the outer cover  6  and the driving circuit board  3 . 
       FIG. 4  is a schematic perspective view illustrating a laser component and a particle sensor accommodated in the base of the gas detection module of the present disclosure. In the embodiment, the laser component  4  and the particle sensor  5  are disposed on the driving circuit board  3  and accommodated in the base  1 . In order to describe the positions of the laser component  4  and the particle sensor  5  in the base  1 , the driving circuit board  3  is specifically omitted in  FIG. 4  to explain clearly. Please refer to  FIG. 4  and  FIG. 2C . The laser component  4  is accommodated in the laser loading region  13  of the base  1 , and the particle sensor  5  is accommodated in the gas-inlet groove  14  of the base  1  and aligned to the laser component  4 . In addition, the laser component  4  spatially corresponds to the transparent window  14   b , a light beam emitted by the laser component  4  passes through the transparent window  14   b  and is irradiated into the gas-inlet groove  14 . A light beam path emitted from the laser component  4  passes through the transparent window  14   b  and forms an orthogonal direction with the gas-inlet groove  14 . 
     In the embodiment, the particle sensor  5  is disposed at an orthogonal position where the gas-inlet groove  14  intersects the light beam path of the laser component  4  in the orthogonal direction, so that suspended particles passing through the gas-inlet groove  14  and irradiated by a projecting light beam emitted from the laser component  4  are detected. 
     In the embodiment, a projecting light beam emitted from the laser component  4  mentioned above passes through the transparent window  14   b  and enters the gas-inlet groove  14 , and suspended particles contained in the gas passing through the gas-inlet groove  14  is irradiated by the projecting light beam. When the suspended particles contained in the gas are irradiated to generate scattered light spots, the scattered light spots are received and calculated by the particle sensor  5  for obtaining related information about the sizes and the concentration of the suspended particles contained in the gas. In the embodiment, the particle sensor  5  is a PM2.5 sensor. 
     Please refer to  FIG. 5A  and  FIG. 5B . The piezoelectric actuator  2  mentioned above is accommodated in the gas-guiding-component loading region  15  of the base  1 . Preferably but not exclusively, the gas-guiding-component loading region  15  is square and includes four positioning protrusions  15   b  disposed at four corners of the gas-guiding-component loading region  15 , respectively. The piezoelectric actuator  2  is disposed in the gas-guiding-component loading region  15  through the four positioning protrusions  15   b . In addition, the gas-guiding-component loading region  15  is in fluid communication with the gas-inlet groove  14 . When the piezoelectric actuator  2  is enabled, the gas in the gas-inlet groove  14  is inhaled by the piezoelectric actuator  2 , so that the gas flows into the piezoelectric actuator  2 . Furthermore, the gas is transported into the gas-outlet groove  16  through the ventilation hole  15   a  of the gas-guiding-component loading region  15 . 
     Please refer to  FIGS. 6A and 6B . In the embodiment, the piezoelectric actuator  2  includes a gas-injection plate  21 , a chamber frame  22 , an actuator element  23 , an insulation frame  24  and a conductive frame  25 . 
     In the embodiment, the gas-injection plate  21  is made by a flexible material and includes a suspension plate  210  and a hollow aperture  211 . The suspension plate  210  is a sheet structure and permitted to undergo a bending deformation. Preferably but not exclusively, the shape and the size of the suspension plate  210  are corresponding to an inner edge of the gas-guiding-component loading region  15 . The shape of the suspension plate  210  is one selected from the group consisting of a square, a circle, an ellipse, a triangle and a polygon. The hollow aperture  211  passes through a center of the suspension plate  210 , so as to allow the gas to flow through. 
     The chamber frame  22  is carried and stacked on the gas-injection plate  21 . In addition, the shape of the chamber frame  22  is corresponding to the gas-injection plate  21 . The actuator element  23  is carried and stacked on the chamber frame  22 . A resonance chamber  26  is collaboratively defined by the actuator element  23 , the chamber frame  22  and the suspension plate  210  and formed among the actuator element  23 , the chamber frame  22  and the suspension plate  210 . The insulation frame  24  is carried and stacked on the actuator element  23  and the appearance of the insulation frame  24  is similar to that of the chamber frame  22 . The conductive frame  25  is carried and stacked on the insulation frame  24 , and the appearance of the conductive frame  25  is similar to that of the insulation frame  24 . In addition, the conductive frame  25  includes a conducting pin  251  and a conducting electrode  252 . The conducting pin  251  is extended outwardly from an outer edge of the conductive frame  25 , and the conducting electrode  252  is extended inwardly from an inner edge of the conductive frame  25 . Moreover, the actuator element  23  further includes a piezoelectric carrying plate  231 , an adjusting resonance plate  232  and a piezoelectric plate  233 . The piezoelectric carrying plate  231  is carried and stacked on the chamber frame  22 . The adjusting resonance plate  232  is carried and stacked on the piezoelectric carrying plate  231 . The piezoelectric plate  233  is carried and stacked on the adjusting resonance plate  232 . The adjusting resonance plate  232  and the piezoelectric plate  233  are accommodated in the insulation frame  24 . The conducting electrode  252  of the conductive frame  25  is electrically connected to the piezoelectric plate  233 . In the embodiment, the piezoelectric carrying plate  231  and the adjusting resonance plate  232  are made by a conductive material. The piezoelectric carrying plate  231  includes a piezoelectric pin  2311 . The piezoelectric pin  2311  and the conducting pin  251  are electrically connected to a driving circuit (not shown) of the driving circuit board  3 , so as to receive a driving signal, such as a driving frequency and a driving voltage. In that, a loop is formed by the piezoelectric pin  2311 , the piezoelectric carrying plate  231 , the adjusting resonance plate  232 , the piezoelectric plate  233 , the conducting electrode  252 , the conductive frame  25  and the conducting pin  251  for the driving signal. Moreover, the insulation frame  24  is insulated between the conductive frame  25  and the actuator element  23 , so as to avoid the occurrence of a short circuit. Thereby, the driving signal is transmitted to the piezoelectric plate  233 . After receiving the driving signal such as the driving frequency and the driving voltage, the piezoelectric plate  233  deforms due to the piezoelectric effect, and the piezoelectric carrying plate  231  and the adjusting resonance plate  232  are further driven to generate the bending deformation in the reciprocating manner. 
     As described above, the adjusting resonance plate  232  is located between the piezoelectric plate  233  and the piezoelectric carrying plate  231  and served as a buffer between the piezoelectric plate  233  and the piezoelectric carrying plate  231 . Thereby, the vibration frequency of the piezoelectric carrying plate  231  is adjustable. Basically, the thickness of the adjusting resonance plate  232  is greater than the thickness of the piezoelectric carrying plate  231 , and the thickness of the adjusting resonance plate  232  is adjustable, thereby adjusting the vibration frequency of the actuator element  23 . 
     Please refer to  FIGS. 6A, 6B, 6C  and  FIG. 7A . In the embodiment, the gas-injection plate  21 , the chamber frame  22 , the actuator element  23 , the insulation frame  24  and the conductive frame  25  are stacked and positioned in the gas-guiding-component loading region  15  sequentially. The piezoelectric actuator  2  is disposed and positioned within the gas-guiding-component loading region  15 , and the bottom of the piezoelectric actuator  2  is disposed and fixed on the positioning protrusions  15   b  for supporting and positioning. Thereby, a plurality of vacant spaces  212  are defined between the suspension plate  210  of the piezoelectric actuator  2  and an inner edge of the gas-guiding-component loading region  15 . The vacant spaces  212  are surrounding the periphery of the piezoelectric actuator  2  for gas flowing. 
     Please refer to  FIG. 7A . A flowing chamber  27  is formed between the gas-injection plate  21  and the bottom surface of the gas-guiding-component loading region  15 . The flowing chamber  27  is in fluid communication with the resonance chamber  26  among the actuator element  23 , the chamber frame  22  and the suspension plate  210  through the hollow aperture  211  of the gas-injection plate  21 . By controlling the vibration frequency of the gas in the resonance chamber  26  to be close to the vibration frequency of the suspension plate  210 , the Helmholtz resonance effect is generated between the resonance chamber  26  and the suspension plate  210 , and thereby the efficiency of gas transportation is improved. 
       FIGS. 7B and 7C  schematically illustrate the actions of the piezoelectric actuator of  FIG. 7A . Please refer to  FIG. 7B . When the piezoelectric plate  233  is moved away from the bottom surface of the gas-guiding-component loading region  15 , the suspension plate  210  of the gas-injection plate  21  is moved away from the bottom surface of the gas-guiding-component loading region  15 . In that, the volume of the flowing chamber  27  is expanded rapidly, the internal pressure of the flowing chamber  27  is decreased to form a negative pressure, and the gas outside the piezoelectric actuator  2  is inhaled through the vacant spaces  212  and enters the resonance chamber  26  through the hollow aperture  211 . Consequently, the pressure in the resonance chamber  26  is increased to generate a pressure gradient. Further as shown in  FIG. 7C , when the suspension plate  210  of the gas-injection plate  21  is driven by the piezoelectric plate  233  to move towards the bottom surface of the gas-guiding-component loading region  15 , the gas in the resonance chamber  26  is discharged out rapidly through the hollow aperture  211 , and the gas in the flowing chamber  27  is compressed. In that, the converged gas close to an ideal gas state of the Benulli&#39;s law is quickly and massively ejected out of the flowing chamber  27  and guided into the ventilation hole  15   a  of the gas-guiding-component loading region  15 . By repeating the above actions shown in  FIG. 7B  and  FIG. 7C , the piezoelectric plate  233  is driven to generate the bending deformation and vibrate in a reciprocating manner. Moreover, according to the principle of inertia, since the gas pressure inside the resonance chamber  26  after exhausting is lower than the equilibrium gas pressure, the gas is introduced into the resonance chamber  26  again. Moreover, the vibration frequency of the gas in the resonance chamber  26  is controlled to be close to the vibration frequency of the piezoelectric plate  233 , so as to generate the Helmholtz resonance effect to achieve the gas transportation at high speed and in large quantities. 
     Please refer to  FIGS. 8A to 8C .  FIGS. 8A to 8C  schematically illustrate gas flowing paths of the gas detection module. Firstly, as shown in  FIG. 8A , the gas is inhaled through the inlet opening  61   a  of the outer cover  6 , flows into the gas-inlet groove  14  of the base  1  through the gas-inlet  14   a , and is transported to the position of the particle sensor  5 . Further as shown in  FIG. 8B , the piezoelectric actuator  2  is enabled continuously to inhale the gas in the inlet path, and it facilitates the gas to be introduced rapidly, flow stably, and be transported above the particle sensor  5 . At this time, a projecting light beam emitted from the laser component  4  passes through the transparent window  14   b  to irritate the suspended particles contained in the gas flowing above the particle sensor  5  in the gas-inlet groove  14 . When the suspended particles contained in the gas are irradiated to generate scattered light spots, the scattered light spots are received and calculated by the particle sensor  5  for obtaining related information about the sizes and the concentration of the suspended particles contained in the gas. Moreover, the gas above the particle sensor  5  is continuously driven and transported by the piezoelectric actuator  2 , flows into the ventilation hole  15   a  of the gas-guiding-component loading region  15 , and is transported to the first section  16   b  of the gas-outlet groove  16 . As shown in  FIG. 8C , after the gas flows into the first section  16   b  of the gas-outlet groove  16 , the gas is continuously transported into the first section  16   b  by the piezoelectric actuator  2 , and the gas in the first section  16   b  is pushed to the second section  16   c . Finally, the gas is discharged out through the gas-outlet  16   a  and the outlet opening  61   b.    
     As shown in  FIG. 9 , the base  1  further includes a light trapping region  17 . The light trapping region  17  is hollowed out from the first surface  11  to the second surface  12  and spatially corresponds to the laser loading region  13 . In the embodiment, the light trapping region  17  is corresponding to the transparent window  14   b  so that the light beam emitted by the laser component  4  is projected into the light trapping region  17 . The light trapping region  17  includes a light trapping structure  17   a  having an oblique cone surface. The light trapping structure  17   a  spatially corresponds to the light beam path emitted from the laser component  4 . In addition, the projecting light beam emitted from the laser component  4  is reflected into the light trapping region  17  through the oblique cone surface of the light trapping structure  17   a . It prevents the projecting light beam from being reflected to the position of the particle sensor  5 . In the embodiment, a light trapping distance D is maintained between the transparent window  14   b  and a position where the light trapping structure  17   a  receives the projecting light beam. Preferably but not exclusively, the light trapping distance D is greater than 3 mm. When the light trapping distance D is less than 3 mm, the projecting light beam projected on the light trapping structure  17   a  is easy to be reflected back to the position of the particle sensor  5  directly due to excessive stray light generated after reflection, and it results in distortion of detection accuracy. 
     Please refer to  FIG. 2C  and  FIG. 9 . The gas detection module  20  of the present disclosure is not only utilized to detect the suspended particles in the gas, but also further utilized to detect the characteristics of the introduced gas, such as detecting formaldehyde, ammonia, carbon monoxide, carbon dioxide, oxygen, ozone, etc. In the embodiment, the gas detection module  20  further includes a first volatile-organic-compound sensor  7   a . The first volatile-organic-compound sensor  7   a  is positioned and disposed on the driving circuit board  3 , electrically connected to the driving circuit board  3 , and accommodated in the gas-outlet groove  16 , so as to detect the gas flowing through the outlet path of the gas-outlet groove  16 . Thus, the concentration or the characteristics of volatile organic compounds contained in the gas in the outlet path is detected. In the embodiment, the gas detection module  20  further includes a second volatile-organic-compound sensor  7   b . The second volatile-organic-compound sensor  7   b  is positioned and disposed on the driving circuit board  3 , and electrically connected to the driving circuit board  3 . In the embodiment, the second volatile-organic-compound sensor  7   b  is accommodated in the light trapping region  17 . Thus, the concentration or the characteristics of volatile organic compounds contained in the gas flowing through the inlet path of the gas-inlet groove  14  and transported into the light trapping region  17  through the transparent window  14   b  is detected. 
     As described above, the gas detection module  20  of the present disclosure is designed to have a proper configuration of the laser loading region  13 , the gas-inlet groove  14 , the gas-guiding-component loading region  15  and the gas-outlet groove  16  on the base  1 . The base  1  is further matched with the outer cover  6  and the driving circuit board  3  to achieve the sealing design. In that, the first surface  11  of the base  1  covers the outer cover  6 , and the second surface  12  of the base  1  covers the driving circuit board  3 , so that the inlet path is collaboratively defined by the gas-inlet groove  14  and the driving circuit board  3 , and the outlet path is collaboratively defined by the gas-outlet groove  16 , the outer cover  6  and the driving circuit board  3 . The gas flowing path is formed in one layer. It facilitates the gas detection module  20  to reduce the thickness of the overall structure. 
     In addition, the piezoelectric actuator  2  in the above embodiment is replaced with a MEMS pump  2   a  in another embodiment. Please refer to  FIG. 10A  and  FIG. 10B . The MEMS pump  2   a  includes a first substrate  21   a , a first oxidation layer  22   a , a second substrate  23   a  and a piezoelectric component  24   a.    
     Preferably but not exclusively, the first substrate  21   a  is a Si wafer and has a thickness ranging from 150 μm to 400 μm. The first substrate  21   a  includes a plurality of inlet apertures  211   a , a first surface  212   a  and a second surface  213   a . In the embodiment, there are four inlet apertures  211   a , but the present disclosure is not limited thereto. Each inlet aperture  211   a  penetrates from the second surface  213   a  to the first surface  212   a . In order to improve the inlet-inflow effect, the plurality of inlet apertures  211   a  are tapered-shaped, and the size is decreased from the second surface  213   a  to the first surface  212   a.    
     The first oxidation layer  22   a  is a silicon dioxide (SiO 2 ) thin film and has the thickness ranging from 10 μm to 20 μm. The first oxidation layer  22   a  is stacked on the first surface  212   a  of the first substrate  21   a . The first oxidation layer  22   a  includes a plurality of convergence channels  221   a  and a convergence chamber  222   a . The numbers and the arrangements of the convergence channels  221   a  and the inlet apertures  211   a  of the first substrate  21   a  are corresponding to each other. In the embodiment, there are four convergence channels  221   a . First ends of the four convergence channels  221   a  are in fluid communication with the four inlet apertures  211   a  of the first substrate  21   a , and second ends of the four convergence channels  221   a  are in fluid communication with the convergence chamber  222   a . Thus, after the gas is inhaled through the inlet apertures  211   a , the gas flows through the corresponding convergence channels  221   a  and is converged into the convergence chamber  222   a.    
     Preferably but not exclusively, the second substrate  23   a  is a silicon on insulator (SOI) wafer, and includes a silicon wafer layer  231   a , a second oxidation layer  232   a  and a silicon material layer  233   a . The silicon wafer layer  231   a  has a thickness ranging from 10 μm to 20 μm, and includes an actuating portion  2311   a , an outer peripheral portion  2312   a , a plurality of connecting portions  2313   a  and a plurality of fluid channels  2314   a . The actuating portion  2311   a  is in a circular shape. The outer peripheral portion  2312   a  is in a hollow ring shape and disposed around the actuating portion  2311   a . The plurality of connecting portions  2313   a  are connected between the actuating portion  2311   a  and the outer peripheral portion  2312   a , respectively, so as to connect the actuating portion  2311   a  and the outer peripheral portion  2312   a  for elastically supporting. The plurality of fluid channels  2314   a  are disposed around the actuating portion  2311   a  and located between the connecting portions  2313   a.    
     The second oxidation layer  232   a  is a silicon monoxide (SiO) layer and has a thickness ranging from 0.5 μm to 2 μm. The second oxidation layer  232   a  is formed on the silicon wafer layer  231   a  and in a hollow ring shape. A vibration chamber  2321   a  is collaboratively defined by the second oxidation layer  232   a  and the silicon wafer layer  231   a . The silicon material layer  233   a  is in a circular shape, disposed on the second oxidation layer  232   a  and bonded to the first oxidation layer  22   a . The silicon material layer  233   a  is a silicon dioxide (SiO 2 ) thin film and has a thickness ranging from 2 μm to 5 μm. In the embodiment, the silicon material layer  233   a  includes a through hole  2331   a , a vibration portion  2332   a , a fixing portion  2333   a , a third surface  2334   a  and a fourth surface  2335   a . The through hole  2331   a  is formed at a center of the silicon material layer  233   a . The vibration portion  2332   a  is disposed around the through hole  2331   a  and vertically corresponds to the vibration chamber  2321   a . The fixing portion  2333   a  is disposed around the vibration portion  2332   a  and located at a peripheral region of the silicon material layer  233   a . The silicon material layer  233   a  is fixed on the second oxidation layer  232   a  through the fixing portion  2333   a . The third surface  2334   a  is connected to the second oxidation layer  232   a . The fourth surface  2335   a  is connected to the first oxidation layer  22   a . The piezoelectric component  24   a  is stacked on the actuating portion  2311   a  of the silicon wafer layer  231   a.    
     The piezoelectric component  24   a  includes a lower electrode layer  241   a , a piezoelectric layer  242   a , an insulation layer  243   a  and an upper electrode layer  244   a . The lower electrode layer  241   a  is stacked on the actuating portion  2311   a  of the silicon wafer layer  231   a . The piezoelectric layer  242   a  is stacked on the lower electrode layer  241   a . The piezoelectric layer  242   a  and the lower electrode layer  241   a  are electrically connected through the contact area thereof. In addition, the width of the piezoelectric layer  242   a  is less than the width of the lower electrode layer  241   a , so that the lower electrode layer  241   a  is not completely covered by the piezoelectric layer  242   a . The insulation layer  243   a  is stacked on a partial surface of the piezoelectric layer  242   a  and a partial surface of the lower electrode layer  241   a , which is uncovered by the piezoelectric layer  242   a . The upper electrode layer  244   a  is stacked on the insulation layer  243   a  and a remaining surface of the piezoelectric layer  242   a  without the insulation layer  243   a  disposed thereon, so that the upper electrode layer  244   a  is contacted and electrically connected with the piezoelectric layer  242   a . At the same time, the insulation layer  243   a  is used for insulation between the upper electrode layer  244   a  and the lower electrode layer  241   a , so as to avoid the short circuit caused by direct contact between the upper electrode layer  244   a  and the lower electrode layer  241   a.    
     Please refer to  FIGS. 11A to 11C .  FIGS. 11A to 11C  schematically illustrate the actions of the MEMS pump. As shown in  FIG. 11A , a driving voltage and a driving signal (not shown) transmitted from the driving circuit board  3  are received by the lower electrode layer  241   a  and the upper electrode layer  244   a  of the piezoelectric component  24   a , and further transmitted to the piezoelectric layer  242   a . After the piezoelectric layer  242   a  receives the driving voltage and the driving signal, the deformation of the piezoelectric layer  242   a  is generated due to the influence of the reverse piezoelectric effect. In that, the actuating portion  2311   a  of the silicon wafer layer  231   a  is driven to displace. When the piezoelectric component  24   a  drives the actuating portion  2311   a  to move upwardly, the actuating portion  2311   a  is separated away from the second oxidation layer  232   a  to increase the distance therebetween. In that, the volume of the vibration chamber  2321   a  of the second oxidation layer  232   a  is expended rapidly, the internal pressure of the vibration chamber  2321   a  is decreased to form a negative pressure, and the gas in the convergence chamber  222   a  of the first oxidation layer  22   a  is inhaled into the vibration chamber  2321   a  through the through hole  2331   a . Further as shown in  FIG. 11B , when the actuating portion  2311   a  is driven by the piezoelectric component  24   a  to move upwardly, the vibration portion  2332   a  of the silicon material layer  233   a  is moved upwardly due to the influence of the resonance principle. When the vibration portion  2332   a  is displaced upwardly, the space of the vibration chamber  2321   a  is compressed and the gas in the vibration chamber  2321   a  is pushed to move to the fluid channels  2314   a  of the silicon wafer layer  231   a . In that, the gas flows upwardly through the fluid channels  2314   a  and is discharged out. Moreover, when the vibration portion  2332   a  is displaced upwardly to compress the vibration chamber  2321   a , the volume of the convergence chamber  222   a  is expended due to the displacement of the vibration portion  2332   a , the internal pressure of the convergence chamber  222   a  is decreased to form a negative pressure, and the gas outside the MEMS pump  2   a  is inhaled into the convergence chamber  222   a  through the inlet apertures  211   a . As shown in  FIG. 11C , when the piezoelectric component  24   a  is enabled to drive the actuating portion  2311   a  of the silicon wafer layer  231   a  to displace downwardly, the gas in the vibration chamber  2321   a  is pushed to flow to the fluid channels  2314   a , and is discharged out. At the same time, the vibration portion  2332   a  of the silicon material layer  233   a  is driven by the actuating portion  2311   a  to displace downwardly, and the gas in the convergence chamber  222   a  is compressed to flow to the vibration chamber  2321   a . Thereafter, when the piezoelectric component  24   a  drives the actuating portion  2311   a  to displace upwardly, the volume of the vibration chamber  2321   a  is greatly increased, and then there is a higher suction force to inhale the gas into the vibration chamber  2321   a . By repeating the above actions, the actuating portion  2311   a  is continuously driven by the piezoelectric component  24   a  to displace upwardly and downwardly, and further to drive the vibration portion  2332   a  to displace upwardly and downwardly. By changing the internal pressure of the MEMS pump  2   a , the gas is inhaled and discharged continuously, thereby achieving the actions of the MEMS pump  2   a.    
     From the above descriptions, the present disclosure provides an external gas detecting device. With the gas detection module embedded in the external gas detecting device, the air quality around the user is detected at any time, and the air quality information is transmitted to the external transmission device in real time. Thus, the gas detection information and the alarm are provided. It is very industrially usable and inventive. 
     While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.