CN116784806A

CN116784806A - Single-chip integrated micro wireless PH detection device and system based on ISFET

Info

Publication number: CN116784806A
Application number: CN202310936870.9A
Authority: CN
Inventors: 胡远奇; 梁菁
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2023-07-28
Filing date: 2023-07-28
Publication date: 2023-09-22

Abstract

This application discloses a single-chip integrated micro wireless pH detection device and system based on ISFET, which relates to the technical field of in vivo pH detection. The device includes: a casing; a wireless sensing chip, the chip is integrated with: a PH sensing module, the sensing interface of which is exposed to the measured environment through the casing; a signal processing module connected to the PH sensing module, for processing the PH sensing signal detected by the PH sensing module; and a wireless communication and power supply module connected to the signal processing module for sending the PH sensing signal processed by the signal processing module, and provides power to each module on the wireless sensing chip. This application integrates the PH detection module, signal processing module, and wireless communication module into an on-chip system, using CMOS technology, wireless energy transmission technology, and backscattering reverse communication technology to effectively reduce the size of the PH detection device and improve PH detection. accuracy.

Description

ISFET-based single-chip integrated miniature wireless PH detection device and system

Technical Field

The application relates to the technical field of in-vivo PH detection, in particular to an ISFET-based single-chip integrated miniature wireless PH detection device and system.

Background

Gastroesophageal reflux disease (Gastroesophageal reflux disease, GERD) is a disease in which gastric contents flow back into the esophagus or pharynx to cause a series of symptoms and complications in the esophagus, and currently, the medical community generally uses 24-hour pH monitoring data as the gold standard for diagnosing GERD symptoms, and the central step of the monitoring process is to place a pH electrode at about 5cm above the esophageal sphincter. The acquired data is then transferred to an in vitro analytical recorder for clinical analysis. In view of the fact that the data acquisition process described above is performed in vivo, and that strict hygiene standards exist in medical environments, the ideal electrode for monitoring pH inside the esophagus should be miniature, reliable and economical.

However, the most widely used and most technically mature pH monitoring systems in the medical market to date are catheter-based, plug-in electrodes, which have a number of limitations. For example, the position of the catheter-type electrode can change along with the body position change of a patient, the actions such as swallowing food and the like, so that measurement data are inaccurate; during the long-term detection, the pH of the catheter electrode slowly drifts over time due to oxidation of the catheter electrode surface. Thus, the accuracy of the data measured using the catheter electrode will decrease after a certain period of time has passed, affecting the diagnostic rate; and the manner in which the catheter is inserted may cause discomfort to the human body.

In addition, there is also a wireless implantable pH monitoring Capsule in the medical market, such as a BRAVO Capsule wireless Capsule. The wireless detection system of the capsule is realized by a plurality of functional module sets, and different modules are required to be electrically connected in a complex way, so that the capsule is large in volume and has certain difficulty in implantation operation and fixation operation; and the problems of oxidation damage on the electrode, short service life of the battery, self-falling and the like are easily caused by long-time monitoring. In addition, the lack of sensitivity of the BRAVO system to short-term reflux events (< 15s to 17 s) may result in loss of data due to the low sampling frequency of the wireless monitoring system.

Disclosure of Invention

In order to solve at least one of the above problems in the prior art, an embodiment of the present application provides a single chip integrated micro wireless PH detection device and system based on ISFET.

According to a first aspect of an embodiment of the present application, there is provided an ISFET-based single chip integrated micro wireless PH detection device, the device comprising:

a housing;

wireless sensing chip, integrate on the chip has:

the PH sensing module is used for exposing a sensing interface of the PH sensing module to the measured environment through the shell;

the signal processing module is connected with the PH sensing module and is used for processing PH sensing signals detected by the PH sensing module; and

and the wireless communication and power supply module is connected with the signal processing module and is used for sending the PH sensing signal processed by the signal processing module and supplying power to each module on the wireless sensing chip.

In one embodiment, the PH sensing module employs an ion sensitive field effect transistor;

the reference electrode of the ion-sensitive field effect transistor is integrated on the chip through a CMOS process.

In an embodiment, the reference electrode is formed on the chip based on magnetron sputtering technology, electron evaporation technology or electroplating technology.

In one embodiment, the sensing interface includes an ion sensitive dielectric layer;

the ion-sensitive dielectric layer comprises one of silicon oxide, silicon nitride, high-K dielectric and metal oxide sensitive to hydrogen ions.

In one embodiment, the signal processing module comprises:

the power amplification unit is used for amplifying the PH sensing signal;

and the analog-to-digital conversion unit is used for performing analog-to-digital conversion on the PH sensing signal amplified by the power amplification unit.

In one embodiment, the wireless communication and power module comprises;

the load modulation keying circuit is connected with the signal processing module and used for transmitting the PH sensing signal processed by the signal processing module;

an on-chip coil connected with the load modulation keying circuit for changing the load according to the regulation of the load modulation keying circuit so as to send the PH sensing signal or receive an external power signal;

and the on-chip power management module is respectively connected with the signal processing module and the PH sensing module and is used for converting the power signal into direct-current power supply voltage to supply power.

In an embodiment, the load modulation keying circuit is further configured to:

when a PH sensing signal sent by the signal processing module is received, controlling the load change of the on-chip coil according to the PH sensing signal so as to enable the on-chip coil to send the PH sensing signal;

and when the PH sensing signal sent by the signal processing module is not received, controlling the load change of the on-chip coil according to the power signal so that the on-chip coil receives the power signal.

In one embodiment, the on-chip power management module includes:

and the on-chip rectifying circuit and the on-chip voltage stabilizing circuit are used for converting the power signal into a stable direct current supply voltage.

In one embodiment, the housing is made of a material that is resistant to corrosion by substances in the environment being tested.

According to a second aspect of an embodiment of the present application, there is provided an ISFET-based single chip integrated micro wireless PH detection system, comprising:

the single-chip integrated miniature wireless PH detection device based on the ISFET is arranged in a detected environment;

the wireless transceiver is arranged in a signal receiving environment different from the measured environment;

the ISFET-based single-chip integrated miniature wireless PH detection device detects PH signals in the detected environment and sends the PH signals to the wireless transceiver; and receiving a power signal transmitted by the wireless transceiver and converting the power signal into a direct current supply voltage.

The single-chip integrated miniature wireless PH detection device and system based on the ISFET adopts the pH sensing circuit based on the ISFET principle, and the volume of the gastric acid monitoring chip system is controlled on the millimeter order of magnitude through micromachining an integrated sensor and an on-chip reference electrode, so that the noninductive implantation is realized, and the high-efficiency, accurate, reliable and quick diagnosis process is realized; meanwhile, the implantation system based on the energy supply of the wireless energy transmission system can further reduce the power consumption of the implant and further improve the safety and reliability of the implant through the medium-far-field energy transmission system, the low-power-consumption power management system and the back-scattering back-communication system. In addition, the semiconductor chip attribute of the ISFET biochip can easily integrate the main body function and the signal processing into a system on a chip, thereby realizing a novel medical diagnosis system with microminiaturization, high precision and reliable performance.

Drawings

In order to more clearly illustrate the embodiments of the application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art. In the drawings:

fig. 1 is a side cross-sectional view of an ISFET-based single chip integrated micro wireless PH detection device provided by the present application.

Fig. 2 is a block diagram of a system structure of a wireless sensor chip according to the present application.

Fig. 3 is a block diagram of another system structure of the wireless sensor chip provided by the present application.

Fig. 4 is a block diagram of another system structure of the wireless sensor chip provided by the present application.

Fig. 5 is a schematic diagram of an ISFET-based single chip integrated micro wireless PH detection system according to the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the embodiments of the present application will be described in further detail with reference to the accompanying drawings. The exemplary embodiments of the present application and their descriptions herein are for the purpose of explaining the present application, but are not to be construed as limiting the application.

According to a first aspect of the embodiment of the present application, the present application provides an ISFET-based single-chip integrated micro wireless PH detection device, fig. 1 is a side cross-sectional view of the ISFET-based single-chip integrated micro wireless PH detection device, and fig. 2 is a system configuration block diagram of a wireless sensor chip. As shown in fig. 1, the apparatus includes: a housing 1 and a wireless sensor chip 2. As shown in fig. 2, a PH sensor module 3, a signal processing module 4, and a wireless communication and power supply module 5 are integrated with the wireless sensor chip 2.

The PH sensing module 3 includes a sensing interface and a sensing circuit. As shown in fig. 1, the sensing interface 31 is exposed to the measured environment through the opening 11 of the housing 1 and is in direct contact with the liquid in the measured environment to acquire the PH signal of the measured environment. Except for the sensing interface 31, the rest parts of the wireless sensing chip 2 are hermetically arranged inside the shell 1 and are not contacted with substances in the measured environment.

When the ISFET-based single-chip integrated miniature wireless PH detection device is used, the ISFET-based single-chip integrated miniature wireless PH detection device is fixed in a detected environment 6, such as human esophagus. The housing 1 and the sensing interface 31 of the ISFET-based single chip integrated micro wireless PH detection device are exposed to the environment to be detected, while the rest of the wireless sensing chip 2 is protected by the housing 1 from being corroded by substances in the environment to be detected. The housing 1 is made of a material resistant to corrosion by substances in the environment to be tested, for example, if the environment to be tested is the esophagus of a human body, the housing 1 should be made of a material resistant to corrosion by gastric acid and having no toxic effect on the human body.

The sensing interface 31 of the PH sensing module 3 is in contact with substances in the detected environment, and a PH sensing signal is obtained by sensing by a sensing circuit; the signal processing module 4 is connected with the PH sensing module 3 and is used for processing PH sensing signals detected by the PH sensing module 3; the wireless communication and power supply module 5 is connected with the signal processing module 4, and is used for sending the PH sensing signal processed by the signal processing module 4 to an external device, receiving a power signal sent by the external device, and converting the power signal into a direct current power supply to supply power for each module of the wireless sensing chip 2. The external device that receives the PH sensing signal and the external device that transmits the power signal may be the same device or may be different devices, which is not limited in the present application.

In the application, the integration of the PH sensing module 3, the signal processing module 4 and the wireless communication and power supply module 5 on the wireless sensing chip 2 can be realized by adopting a CMOS process, and as the modules are integrated on the same chip, the size of the single-chip integrated miniature wireless PH detection device based on the ISFET can be effectively reduced, and when the miniature wireless PH detection device is implanted into a human body, the miniature wireless PH detection device is beneficial to reducing the uncomfortable feeling of the human body and bringing more comfortable treatment experience to the human body. Meanwhile, the wireless communication and power supply module 5 adopts a wireless energy transmission technology and a back scattering technology to realize communication and power supply, and as the communication and the power supply share the same channel, the number of communication coils is reduced, the integration level of the device can be further improved, and the data transmission power consumption is reduced.

In one embodiment, PH sensing module 2 employs an ion sensitive field effect transistor ISFET; and the reference electrode of the ISFET is integrated on the wireless sensor chip 2 by CMOS process.

Conventional ISFETs require an external reference electrode to provide a stable potential to the environment being measured. The external reference electrode is relatively bulky, typically on the order of millimeters (mm) or centimeters (cm). The application realizes on-chip integration of the reference electrode of the ISFET based on the CMOS process, and integrates the reference electrode on the wireless sensing chip 2. Because no external reference electrode is needed, the size of the whole ISFET-based single-chip integrated miniature wireless PH detection device is greatly reduced.

The structure can design the reference electrode as a part of the chip by using the CMOS technology while producing the wireless sensing chip 2, and then form the reference electrode on the wireless sensing chip based on the technologies such as the magnetron sputtering technology, the electronic vapor deposition technology or the electroplating technology, thereby realizing the arrangement of the area of the reference electrode on the chip, fixing the distance between the reference electrode and the sensing front end and greatly improving the sensitivity and the accuracy of the detection system. Meanwhile, the size of the reference electrode is also obviously reduced, and the reference electrode and the sensing circuit are positioned on the same plane, so that the total volume of the ISFET-based single-chip integrated miniature wireless PH detection device can be effectively reduced.

Taking an Ag/AgCl reference electrode as an example, when the on-chip reference electrode is prepared, a designated area of the reference electrode on the chip can be designed by utilizing a CMOS process, then silver (Ag) materials are sputtered in the designated area on the chip by using a magnetron sputtering technology, an electronic vapor deposition technology or an electroplating technology and the like, and the thickness of the silver materials can be adjusted as required and is generally in the um level; and then carrying out electrode reaction with HCL to generate AgCl on the surface of Ag, thereby realizing the preparation of the on-chip reference electrode.

the ion-sensitive dielectric layer includes, but is not limited to, one of silicon oxide, silicon nitride, tantalum oxide, aluminum oxide, high-K dielectric, metal oxide sensitive to hydrogen ions. In practical application, the material of the ion sensitive medium layer of a proper type can be selected according to the requirement on the working frequency in a use scene.

The application is not limited by the process or technique used to form the ion sensitive dielectric layer. The process or technology adopted when the ion sensitive dielectric layer grows on the sensing interface can be different according to the difference of materials of the ion sensitive dielectric layer, for example, for silicon oxide and silicon nitride, the growth can be realized based on a CMOS process; for high-K medium and metal oxide sensitive to hydrogen ions, deposition and other processes can be used to realize growth. In practical application, a suitable process or technology is selected, and the application is not limited to this.

In one embodiment, as shown in fig. 3, the signal processing module 4 includes:

a power amplifier 41, configured to amplify the PH sensing signal;

and the analog-to-digital conversion unit 42 is used for performing analog-to-digital conversion on the PH sensing signal amplified by the power amplification unit.

The power amplifier unit 41 and the analog-to-digital conversion unit 42 can be designed with extremely low power consumption, for example, the power consumption requirement of the signal processing module can be reduced from the aspects of architecture, working mode and the like; meanwhile, the ultra-low power consumption digital unit can be used for design, so that the power supply using scheme and the low power consumption requirement of the whole device are further met.

In one embodiment, as shown in fig. 4, the wireless communication and power module 5 includes;

a load modulation keying (load shift keying, LSK) circuit 51 connected to the signal processing module 4 for transmitting the PH sensing signal processed by the signal processing module 4;

an on-chip coil 52 connected to the load modulation keying circuit 51 for changing a load according to the regulation of the load modulation keying circuit 51 to transmit a PH sensing signal or receive an external power signal;

the on-chip power management module 53 is connected to the signal processing module 4 and the PH sensing module 3, and is configured to convert the power signal received by the on-chip coil 52 into a dc power supply voltage for power supply.

When the load modulation keying circuit 51 receives the PH sensing signal sent by the signal processing module, the load variation of the on-chip coil 52 is controlled according to the PH sensing signal, so that the on-chip coil 52 sends the PH sensing signal, and a wireless communication function is realized;

when the load modulation keying circuit 51 does not receive the PH sensing signal sent by the signal processing module, the load change of the on-chip coil 52 is controlled according to the power signal, so that the on-chip coil receives the power signal sent by the external device, and the on-chip power management module 53 further converts the power signal into a direct-current power supply voltage to supply power, thereby realizing a wireless power supply function.

Taking the on-chip coil 52 as an example for transmitting and receiving binary signals, it is assumed that the load of the on-chip coil 52 can vary between 0 and R according to the control of the load modulation keying circuit 51, and when the load of the on-chip coil 52 is preset to a first load value a, it is equivalent to transmitting a digital signal "1", and when the load of the on-chip coil 52 is set to a second load value b, it is equivalent to transmitting a digital signal "0", wherein the first load value a and the second load value b satisfy: a is more than or equal to 0 and less than or equal to R, b is more than or equal to 0 and less than or equal to R, a is not equal to b, and the difference value between the first load value a and the second load value b is larger than a preset threshold value x, and x is more than or equal to 0 and less than or equal to R. In practice, x is set so that a and b can be clearly distinguished.

In the case where the PH sensing module 3 detects a PH sensing signal, the wireless communication implementation flow is as follows:

(1) The PH sensing module 3 detects PH sensing signals and sends the PH sensing signals to the signal processing module 4; the PH sensing signal at this time is an analog signal, and thus may also be referred to as a PH sensing analog signal;

(2) The signal processing module 4 performs amplification, analog-to-digital conversion and other processes on the PH sensing analog signal, and sends the PH sensing analog signal to the load modulation keying circuit 51; the PH sensing signal processed by the signal processing module 4 is a digital signal, and thus may also be referred to as a PH sensing digital signal;

(3) The load modulation keying circuit 51 receives the PH sensing digital signal and transmits the PH sensing digital signal to the on-chip coil 52; meanwhile, the load modulation keying circuit 51 regulates and controls the load of the on-chip coil 52 according to the PH sensing digital signal, and controls the load value of the load to be continuously changed into a first load value a corresponding to the binary digit "1" or a second load value b corresponding to the binary digit "0".

At this time, the load change is determined according to the PH sensing digital signal, for example, assuming that the PH sensing digital signal detected at a time is 0111001 … …, the load modulation keying circuit 51 controls the load to change to b, a, a, a, b, b, a … … in sequence, and it is understood that the PH sensing signal detected by the PH sensing module 3 may also change as the measured environment changes or the content in the measured environment changes, that is, the PH sensing signal detected by the PH sensing module may be the same or different each time. The load modulation keying circuit 51 controls the load value of the load differently when receiving different PH sensing signals.

The load modulation keying circuit 51 controls the load to switch back and forth between the first load value a and the second load value b according to the PH sensing digital signal, so that the on-chip coil 53 sends the PH sensing digital signal to an external device (for example, an external signal receiving device) outside the measured environment, so that equipment outside the measured environment can receive, record, store and analyze the PH environment in the measured environment, and the wireless communication function of the PH sensing signal is realized.

In the case where the PH sensing module 3 does not detect the PH sensing signal, that is, when the load modulation keying circuit 51 does not receive the PH sensing signal, the wireless power supply implementation flow is as follows:

(1) A power signal transmitted by an external device (e.g., an external signal transmitting device) outside the measured environment, for example, a sinusoidal signal of a specific frequency.

(2) The load modulation keying circuit 51 regulates and controls the load of the on-chip coil 52 according to a preset control mode corresponding to the power signal, and controls the load value of the load to be continuously changed into a first load value a corresponding to a binary number "1" or a second load value b corresponding to a binary number "0".

At this time, the control method of the load modulation keying circuit 51 corresponds to the power signal, for example, assuming that the power signal is 01010101 … …, the value of the load controlled by the load modulation keying circuit 51 is sequentially changed to b, a, b, a, b, a, b, a … …, and it is understood that, in order to ensure the implementation of the wireless power supply function, the power signal of the present application is a fixed signal set in advance, and at the same time, the control method of the load by the load modulation keying circuit 51 when the PH sensing signal is not received is set to a fixed control method corresponding to the fixed signal. Alternatively, the power signal of the present application may be changed, but the load modulation and keying circuit 51 needs to correspondingly change the control mode of the load when the PH sensing signal is not received while changing the power signal.

The load modulation and keying circuit 51 controls the load to switch back and forth between the first load value a and the second load value b according to a preset control mode corresponding to a power signal sent by an external device (for example, an external signal sending device) outside the tested environment, so that the on-chip coil 53 receives the power signal, and the on-chip power management module 53 converts the power signal into a direct current supply voltage to supply power, thereby realizing a wireless power supply function based on the power signal.

In the application, the wireless communication and power supply module 5 adopts the wireless energy transmission technology to supply power, and simultaneously adopts the back scattering technology to carry out reverse communication, and only one coil is needed because the power supply and the communication process share the same channel, thereby further improving the integration level of the device and reducing the power consumption of data transmission. The wireless communication and power supply module 5 is designed by adopting a middle-far field wireless energy transmission technology, and compared with near-field inductive coupling, the mode of transmitting energy by the middle-field electromagnetic radiation comprises near-field inductive coupling and partial far-field electromagnetic radiation, the distance between receiving and transmitting coils is farther, and the coil size is smaller.

In one embodiment, the on-chip power management module 53 includes an on-chip rectifying circuit and an on-chip voltage stabilizing circuit for converting the power signal into a stable dc supply voltage.

The on-chip rectifying circuit and the on-chip voltage stabilizing circuit can work under lower power supply voltage by utilizing the working characteristics of the subthreshold region and the body driving design to be matched with a wireless energy transmission system, and meanwhile, the design without an off-chip capacitor and the diode rectifying circuit can improve the integration level and reduce the volume of the implanted equipment.

According to a second aspect of the embodiment of the present application, the present application provides an ISFET-based single-chip integrated micro wireless PH detection system, and fig. 5 is a schematic diagram of the ISFET-based single-chip integrated micro wireless PH detection system. As shown in fig. 5, the system 100 includes:

the ISFET-based single-chip integrated miniature wireless PH detection device 101 is arranged in a detected environment;

a wireless transceiver 102 disposed in a signal receiving environment different from the measured environment;

an ISFET-based single-chip integrated micro wireless PH detection device 101 detects a PH signal in a measured environment and transmits the PH signal to a wireless transceiver 102; the ISFET-based single chip integrated micro wireless PH detection device 101 also receives the power signal transmitted by the wireless transceiver 102 and converts the power signal to a dc supply voltage. The ISFET-based single-chip integrated micro wireless PH detection device 101 of the system 100 may be any one of the ISFET-based single-chip integrated micro wireless PH detection devices provided in the embodiments of the present application, and in particular, reference may be made to the related embodiments of the present application, which will not be repeated herein.

In practical application, the tube with the ISFET-based single-chip integrated miniature wireless PH detection device is inserted into a landing point in the esophagus of a patient, and the ISFET-based single-chip integrated miniature wireless PH detection device is fixed on the esophagus by a feasible method. The PH sensing module of the single-chip integrated miniature wireless PH detection device based on the ISFET monitors the PH value of the environment in real time, and amplifies and converts the signals through the signal processing module. And then the wireless communication module in the single-chip integrated miniature wireless PH detection device based on the ISFET performs wireless communication with the communication module worn outside the patient, so that the transmission and the recording of monitoring data are realized, the gastric acid reflux condition inside the esophagus of the patient is recorded, and after a period of time, the single-chip integrated miniature wireless PH detection device based on the ISFET automatically drops off along with the tissue of the inner wall of the esophagus and is discharged outside along with the digestive system of the human body, so that the monitoring work is completed.

The single-chip integrated miniature wireless PH detection system based on the ISFET adopts the pH sensing circuit based on the ISFET principle, and the volume of the gastric acid monitoring chip system is controlled on the millimeter order by micromachining an integrated sensor and an on-chip reference electrode, so that the noninductive implantation is realized, and the high-efficiency, accurate, reliable and quick diagnosis process is realized; meanwhile, the implantation system based on the energy supply of the wireless energy transmission system can further reduce the power consumption of the implant and further improve the safety and reliability of the implant through the medium-far-field energy transmission system, the low-power-consumption power management system and the back-scattering back-communication system. In addition, the semiconductor chip attribute of the ISFET biochip can easily integrate the main body function and the signal processing into a system on a chip, thereby realizing a novel medical diagnosis system with microminiaturization, high precision and reliable performance.

The foregoing description of the embodiments has been provided for the purpose of illustrating the general principles of the application, and is not meant to limit the scope of the application, but to limit the application to the particular embodiments, and any modifications, equivalents, improvements, etc. that fall within the spirit and principles of the application are intended to be included within the scope of the application.

Claims

1. An ISFET-based single chip integrated micro wireless PH detection device, the device comprising:

a housing;

wireless sensing chip, integrate on the chip has:

2. The ISFET-based single-chip integrated micro wireless PH detection device of claim 1, wherein the PH sensing module employs an ion sensitive field effect transistor;

3. The ISFET-based single-chip integrated micro wireless PH detection device of claim 2, wherein the reference electrode is formed on the chip based on magnetron sputtering technology, electron evaporation technology, or electroplating technology.

4. The ISFET-based single-chip integrated micro wireless PH detection device of claim 1, wherein the sensing interface comprises an ion-sensitive dielectric layer;

5. The ISFET-based single-chip integrated micro wireless PH detection device of claim 1, wherein the signal processing module comprises:

the power amplification unit is used for amplifying the PH sensing signal;

6. The ISFET-based single-chip integrated micro wireless PH detection device of claim 1, wherein the wireless communication and power module comprises;

7. The ISFET-based single-chip integrated micro wireless PH detection device of claim 6, wherein the load modulation keying circuit is further configured to:

8. The ISFET-based single-chip integrated micro wireless PH detection device of claim 6, wherein the on-chip power management module comprises:

9. The ISFET-based single-chip integrated micro wireless PH detection device of claim 1, wherein the housing is made of a material that is resistant to corrosion by substances in the environment being tested.

10. An ISFET-based single chip integrated micro wireless PH detection system, said system comprising:

the ISFET-based single chip integrated micro wireless PH sensing device of any one of claims 1 to 9 disposed in an environment to be sensed;