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A Meliorated Multi-Frequency Band Pyroelectric Sensor.

Hsiao CC, Liu SY, Siao AS - Sensors (Basel) (2015)

Bottom Line: The proposed sensor is built on a silicon substrate with a thermal isolation layer of a silicon nitride film, consisting of four pyroelectric layers with various thicknesses deposited by a sputtering or aerosol deposition (AD) method and top and bottom electrodes.The fabricated device is effective in the range of 1 KHz~10 KHz with a rapid response and high voltage responsivity, while the ZnO layers with thicknesses of about 0.8 μm, 6 μm, 10 μm and 16 μm are used for fabricating the meliorated multi-frequency band pyroelectric sensor.The proposed sensor is successfully designed, analyzed, and fabricated in the present study, and can indeed extend the sensing range of the multi-frequency band.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Design Engineering, National Formosa University, No. 64, Wunhua Rd., Huwei Township, Yunlin County 632, Taiwan. cchsiao@nfu.edu.tw.

ABSTRACT
This article proposes a meliorated multi-frequency band pyroelectric sensor for detecting subjects with various velocities, namely extending the sensing frequency under good performance from electrical signals. A tactic, gradually increasing thickness of the ZnO layers, is used for redeeming drawbacks of a thicker pyroelectric layer with a tardy response at a high-frequency band and a thinner pyroelectric layer with low voltage responsivity at a low-frequency band. The proposed sensor is built on a silicon substrate with a thermal isolation layer of a silicon nitride film, consisting of four pyroelectric layers with various thicknesses deposited by a sputtering or aerosol deposition (AD) method and top and bottom electrodes. The thinnest ZnO layer is deposited by sputtering, with a low thermal capacity and a rapid response shoulders a high-frequency sensing task, while the thicker ZnO layers are deposited by AD with a large thermal capacity and a tardy response shoulders a low-frequency sensing task. The fabricated device is effective in the range of 1 KHz~10 KHz with a rapid response and high voltage responsivity, while the ZnO layers with thicknesses of about 0.8 μm, 6 μm, 10 μm and 16 μm are used for fabricating the meliorated multi-frequency band pyroelectric sensor. The proposed sensor is successfully designed, analyzed, and fabricated in the present study, and can indeed extend the sensing range of the multi-frequency band.

No MeSH data available.


Measured Voltage responsivities of the meliorated multi-frequency band pyroelectric sensor with TPZ = 0.8 μm, TAZ3 = 6 μm, TAZ2 = 10 μm and TAZ1 = 16 μm under an incident irradiation power modulated by various chopping frequencies of about (a) 1 KHz, (b) 3 KHz, (c) 10 KHz and (d) 30 KHz.
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sensors-15-16248-f011: Measured Voltage responsivities of the meliorated multi-frequency band pyroelectric sensor with TPZ = 0.8 μm, TAZ3 = 6 μm, TAZ2 = 10 μm and TAZ1 = 16 μm under an incident irradiation power modulated by various chopping frequencies of about (a) 1 KHz, (b) 3 KHz, (c) 10 KHz and (d) 30 KHz.

Mentions: An experimental setup was used to verify the above analytical results. The IR laser beam was chopped and molded as a square wave with various modulated frequencies (1 KHz, 3 KHz, 10 KHz and 30 KHz) to obtain temperature variation rates in the meliorated multi-frequency band pyroelectric device by a programmable function generator. Figure 11 shows the voltage responsivities of the fabricated multi-frequency band pyroelectric device with TPZ = 0.8 μm, TAZ3 = 6 μm, TAZ2 = 10 μm and TAZ1 = 16 μm when the incident irradiation power was modulated by various chopping frequencies of about 1 KHz, 3 KHz, 10 KHz and 30 KHz. The amplitude of the integrated voltage responsivity of VT increased while chopping frequencies decreased due to the increasing period to absorb thermal energy. VT presented almost a square form. This indicated that the response time was hardly affected by using various thicknesses of ZnO layers at these frequencies. Moreover, the intensity of VT was almost identical when using various thicknesses of ZnO layers at a fixed frequency. The fabricated multi-frequency band pyroelectric device at a modulated frequency of 1 KHz presented a low-frequency property. The intensity of VT increased, and it did not possess a tardy response. Furthermore, the fabricated multi-frequency band pyroelectric device at a modulated frequency of 10 KHz presented a high-frequency property. Although the intensity of VT decreased, the sensing frequency band increased. This implied that the voltage responsivity could hold on a peak value with a larger sensing frequency band. However, a higher frequency of 30 KHz was over the multi-frequency band range of the fabricated device. Although the intensity of VT was improved, the sensing frequency bands of VT and VP were the same due to the weaknesses of VA1, VA2 and VA3 at higher frequencies. Therefore, the fabricated multi-frequency band pyroelectric device was effective in the range of 1 KHz~10 KHz with a rapid response and large voltage responsivity. Hence, the multi-frequency band pyroelectric device could enhance pyroelectric sensors detecting subjects with various speeds or frequencies without dependence on the thicknesses of the pyroelectric elements.


A Meliorated Multi-Frequency Band Pyroelectric Sensor.

Hsiao CC, Liu SY, Siao AS - Sensors (Basel) (2015)

Measured Voltage responsivities of the meliorated multi-frequency band pyroelectric sensor with TPZ = 0.8 μm, TAZ3 = 6 μm, TAZ2 = 10 μm and TAZ1 = 16 μm under an incident irradiation power modulated by various chopping frequencies of about (a) 1 KHz, (b) 3 KHz, (c) 10 KHz and (d) 30 KHz.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541877&req=5

sensors-15-16248-f011: Measured Voltage responsivities of the meliorated multi-frequency band pyroelectric sensor with TPZ = 0.8 μm, TAZ3 = 6 μm, TAZ2 = 10 μm and TAZ1 = 16 μm under an incident irradiation power modulated by various chopping frequencies of about (a) 1 KHz, (b) 3 KHz, (c) 10 KHz and (d) 30 KHz.
Mentions: An experimental setup was used to verify the above analytical results. The IR laser beam was chopped and molded as a square wave with various modulated frequencies (1 KHz, 3 KHz, 10 KHz and 30 KHz) to obtain temperature variation rates in the meliorated multi-frequency band pyroelectric device by a programmable function generator. Figure 11 shows the voltage responsivities of the fabricated multi-frequency band pyroelectric device with TPZ = 0.8 μm, TAZ3 = 6 μm, TAZ2 = 10 μm and TAZ1 = 16 μm when the incident irradiation power was modulated by various chopping frequencies of about 1 KHz, 3 KHz, 10 KHz and 30 KHz. The amplitude of the integrated voltage responsivity of VT increased while chopping frequencies decreased due to the increasing period to absorb thermal energy. VT presented almost a square form. This indicated that the response time was hardly affected by using various thicknesses of ZnO layers at these frequencies. Moreover, the intensity of VT was almost identical when using various thicknesses of ZnO layers at a fixed frequency. The fabricated multi-frequency band pyroelectric device at a modulated frequency of 1 KHz presented a low-frequency property. The intensity of VT increased, and it did not possess a tardy response. Furthermore, the fabricated multi-frequency band pyroelectric device at a modulated frequency of 10 KHz presented a high-frequency property. Although the intensity of VT decreased, the sensing frequency band increased. This implied that the voltage responsivity could hold on a peak value with a larger sensing frequency band. However, a higher frequency of 30 KHz was over the multi-frequency band range of the fabricated device. Although the intensity of VT was improved, the sensing frequency bands of VT and VP were the same due to the weaknesses of VA1, VA2 and VA3 at higher frequencies. Therefore, the fabricated multi-frequency band pyroelectric device was effective in the range of 1 KHz~10 KHz with a rapid response and large voltage responsivity. Hence, the multi-frequency band pyroelectric device could enhance pyroelectric sensors detecting subjects with various speeds or frequencies without dependence on the thicknesses of the pyroelectric elements.

Bottom Line: The proposed sensor is built on a silicon substrate with a thermal isolation layer of a silicon nitride film, consisting of four pyroelectric layers with various thicknesses deposited by a sputtering or aerosol deposition (AD) method and top and bottom electrodes.The fabricated device is effective in the range of 1 KHz~10 KHz with a rapid response and high voltage responsivity, while the ZnO layers with thicknesses of about 0.8 μm, 6 μm, 10 μm and 16 μm are used for fabricating the meliorated multi-frequency band pyroelectric sensor.The proposed sensor is successfully designed, analyzed, and fabricated in the present study, and can indeed extend the sensing range of the multi-frequency band.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Design Engineering, National Formosa University, No. 64, Wunhua Rd., Huwei Township, Yunlin County 632, Taiwan. cchsiao@nfu.edu.tw.

ABSTRACT
This article proposes a meliorated multi-frequency band pyroelectric sensor for detecting subjects with various velocities, namely extending the sensing frequency under good performance from electrical signals. A tactic, gradually increasing thickness of the ZnO layers, is used for redeeming drawbacks of a thicker pyroelectric layer with a tardy response at a high-frequency band and a thinner pyroelectric layer with low voltage responsivity at a low-frequency band. The proposed sensor is built on a silicon substrate with a thermal isolation layer of a silicon nitride film, consisting of four pyroelectric layers with various thicknesses deposited by a sputtering or aerosol deposition (AD) method and top and bottom electrodes. The thinnest ZnO layer is deposited by sputtering, with a low thermal capacity and a rapid response shoulders a high-frequency sensing task, while the thicker ZnO layers are deposited by AD with a large thermal capacity and a tardy response shoulders a low-frequency sensing task. The fabricated device is effective in the range of 1 KHz~10 KHz with a rapid response and high voltage responsivity, while the ZnO layers with thicknesses of about 0.8 μm, 6 μm, 10 μm and 16 μm are used for fabricating the meliorated multi-frequency band pyroelectric sensor. The proposed sensor is successfully designed, analyzed, and fabricated in the present study, and can indeed extend the sensing range of the multi-frequency band.

No MeSH data available.