In this study, a microwave slot-antenna loaded with complementary split ring resonator (CSRR) for wireless temperature-pressure detection in high-temperature environments was presented. To achieve the design of a miniaturized high-temperature sensor with multiple parameters, it is proposed to use a S11 to simultaneously monitor temperature and pressure parameters. Using resonant amplitude to monitor changes in environmental temperature and using resonant frequency to characterize changes in pressure. The sensitivity mechanisms for the temperature, and pressure sensing are described in detail. The working principle of the temperature-pressure sensor is elaborated via circuit analysis and simulation optimization of high frequency structure simulator (HFSS). The sensor was customized and fabricated on the high temperature cofired ceramics (HTCC) using the three-dimensional co-firing and screen-printing technology. The as-prepared sensor can stably work at the ambient environment of 20 - 800 ℃, and 100 - 300 kPa, with a temperature sensitivity of 0.0133 dB/°C and a pressure sensitivity of 235 kHz/kPa at 800 °C. The temperature compensation algorithm is proposed to achieve accurate acquisition of pressure signals in a high-temperature environment. The sensor has the potential for utilization in simultaneous temperature and pressure monitoring in harsh environments.

A passive substrate integrated waveguide (SIW) sensor based on the complementary split ring resonator (CSRR) is presented for pressure detection in high-temperature environments. The sensor pressure sensing mechanism is described through circuit analysis and the electromagnetic coupling principle. The pressure sensor is modeled in high frequency structure simulator (HFSS), designed through parameter optimization. According to the optimized parameters, the sensor was customized and fabricated on a high temperature co-fired ceramic (HTCC) substrate using the three-dimensional co-fired technology and screen-printing technology. The pressure sensor was tested in the high-temperature pressure furnace and can work stably in the ambient environment of 25−500 °C and 10−300 kPa. The pressure sensitivity is 139.77 kHz/kPa at 25 °C, and with increasing temperature, the sensitivity increases to 191.97 kHz/kPa at 500 °C. The temperature compensation algorithm is proposed to achieve accurate acquisition of pressure signals in a high-temperature environment.

A novel, wireless, passive substrate-integrated waveguide (SIW) temperature sensor based on a complementary split-ring resonator (CSRR) is presented for ultra-high-temperature applications. The temperature sensor model was established by using the software of HFSS (ANSYS, Canonsburg, PA, USA) to optimize the performance. This sensor can monitor temperature wirelessly using the microwave backscatter principle, which uses a robust high-temperature co-fired ceramic (HTCC) as the substrate for harsh environments. The results are experimentally verified by measuring the S (1,1) parameter of the interrogator antenna without contact. The resonant frequency of the sensor decreases with the increasing temperature using the dielectric perturbation method, which changes from 2.5808 to 2.35941 GHz as the temperature increases from 25 to 1200 °C. The sensitivity of the sensor is 126.74 kHz/°C in the range of 25–400 °C and 217.33 kHz/°C in the range of 400–1200 °C. The sensor described in this study has the advantages of simple structure, higher quality and sensitivity, and lower environmental interference, and has the potential for utilization in multi-site temperature testing or multi-parameter testing (temperature, pressure, gas) in high-temperature environments.

Flexible pressure sensors show great promise for applications in such fields as electronic skin, healthcare, and intelligent robotics. Traditional capacitive pressure sensors, however, face the problem of low sensitivity, which limits their wider application. In this paper, a flexible capacitive pressure sensor with microstructured ionization layer is fabricated by a sandwich-type process, with a low-cost and simple process of inverted molding with sandpapers being used to form a thermoplastic polyurethane elastomer ionic film with double-sided microstructure as the dielectric layer of the sensor, with silver nanowires as electrodes. The operating mechanism of this iontronic pressure sensor is analyzed using a graphical method, and the sensor is tested on a pressure platform. The test results show that the sensor has ultrahigh pressure sensitivities of 3.744 and 1.689 kPa−1 at low (0–20 kPa) and high (20–800 kPa) pressures, respectively, as well as a rapid response time (100 ms), and it exhibits good stability and repeatability. The sensor can be used for sensitive monitoring of activities such as finger bending, and for facial expression (smile, frown) recognition, as well as speech recognition.

With the rapid development of electronic devices, flexible pressure sensors have been widely used in many fields such as robot skin and wearable devices. However, designing a flexible pressure sensor with high sensitivity, a wide detection range, and easy preparation remains a formidable challenge. In this study, high-elastic sponge is selected as the base material, and silver nanowires (AgNWs) and two-dimensional transition metal carbides (MXENEs) are used as conductive materials. At the same time, AgNWs and PI tape are used as the electrode layer and encapsulation layer, respectively. A resistive flexible pressure sensor based on AgNWs–MXENE sponge is successfully prepared using sandwich encapsulation, and a series of performance tests and practical application tests are carried out on it. The test results show that the sensor has a wide detection range (0–1000 kPa). When the concentration of AgNWs–MXENE is 6%, the sensitivity of the prepared sensor reaches the highest value. Under the pressure of 0–2 kPa, it has a high sensitivity of 0.4901 kPa−1, as well as good response time (100 ms), good stability, and repeatability. It can also accurately detect the tiny and large pressures generated by activities such as pressing, making sounds, swallowing, and bending. This is of great significance for the accurate operation of robots, the functional optimization of wearable devices, and the improvement of the accuracy of health monitoring, and it has broad application prospects in the fields of robot skin, wearable electronic devices, health monitoring, and human–machine interaction.

This study presents a highly sensitive wireless passive flexible pressure sensor. The sensor employs an ionic film as the dielectric layer, utilizes a spiral coil as the antenna for transmitting and receiving signals of the sensor, and adopts a sandwich process to complete the fabrication of the sensor. This study validates through circuit analysis and simulation that the sensor can be used for wireless passive detection of pressure information. Firstly, the performance of the ionic film is examined. The sensor fabricated with the ionic film has high sensitivity (38.74 N ^-1 ), fast response time (100 ms), and high stability. This study also tests the wireless transmission performance between the sensor and the antenna. The test results indicate that the sensor can achieve wireless signal detection within a range of 13 mm. The pressure sensitivity of the sensor in the range of 0 - 0.5 N is 394.94 MHz/N. When the applied pressure increases from 0.5 N to 10 N, the resonant frequency of the sensor decreases from 210 MHz to 160 MHz, and the pressure sensitivity is 4.15 MHz/N. The sensor can realize palm bending detection, breathing, and voice recognition, and has extensive application prospects in the fields of human-computer interaction and wearables.