Parameters for Pressure Sensors: History
View Latest Version
Please note this is an old version of this entry, which may differ significantly from the current revision.
Contributor:
Wen-Tao Guo
,
Xin-Gui Tang
,
Zhenhua Tang
,
Qi-Jun Sun

Pressure sensors show significant potential applications in health monitoring, bio-sensing, electronic skin, and tactile perception. Consequently, tremendous research interest has been devoted to the development of high-performance pressure sensors.

  • polymer composites
  • pressure sensors
  • wearable electronics

1. Introduction

As an electronic device for detecting and transmitting information, the pressure sensor has the ability to perceive pressure signals and transform them into corresponding electrical signals. This enables the sensor to collect, transmit, process, analyze, and display information. Tactile perception [1][2][3][4], medical monitoring [5][6][7][8], wearable electronic products [9][10][11][12][13], and human motion detection [14][15][16] have emerged as popular application themes in the area of pressure sensors, especially in the previous few years. The classical pressure sensor ground on Micro-Electro-Mechanical Systems (MEMS) mainly consists of metal, semiconductors, piezoelectric crystals, etc., which are usually rigid materials. The technique of utilizing these materials to fabricate pressure sensors is proven and can precisely achieve remarkable performance in terms of low measurement errors and mass fabrication [17][18][19][20][21]. However, their shortcomings include the large volume and limited deformation. Others have hindered their application in human motion detection, health monitoring, and other scenes. Therefore, developing flexible pressure sensors that can bend and deform without losing performance is vital for expanding their potential uses in wearable devices and robotic systems.
Generally, based on different conduction mechanisms, pressure sensing devices can be basically classified into five types, including capacitive [9][11][22][23][24][25][26], piezoresistive [14][27][28][29][30], piezoelectric [15][31][32][33][34][35], triboelectric [36][37][38][39][40], and magnetoelastic [41][42][43] pressure sensors (Figure 1). In recent years, researchers have shown great research interest in capacitive and piezoresistive pressure sensors due to their straightforward device configuration and convenient signal processing. Meanwhile, piezoelectric, triboelectric, and magnetoelastic pressure sensors have the advantage of being self-powered, requiring no input external current or voltage to operate. While these sensors exhibit reliable dynamic pressure detection, achieving reliable static pressure detection remains challenging.
Polymers 15 02176 g001
Figure 1. Pressure sensors with different working principles: (a) Capacitive; (b) Piezoresistive; (c) Piezoelectric; (d) Triboelectric; (e) Magnetoelastic.
These sensors take on different forms, such as capacitive, piezoresistive, piezoelectric, triboelectric, and magnetoelastic sensors. The sensing principles and representative examples of these sensors are introduced and discussed. Numerous studies have demonstrated the feasibility of wearable sensing devices for health monitoring, electronic skin, and human physiology detection.
In the future, polymer-based pressure sensors are expected to have more advantages over other sensors or sensing technologies, such as high sensitivity, low cost, simple fabrication, and biocompatibility. Some of the potential applications of these sensors include artificial organs, electronic skin, health monitoring, and environmental detection. To achieve these goals, some of the research directions that need to be explored are: (1) Developing novel polymer materials or composites with tunable electrical and mechanical properties. (2) Improving the sensitivity and selectivity to different types of pressure. (3) Integrating polymer-based pressure sensors with other types of sensing devices, such as temperature, humidity, or chemical sensors, to form multifunctional sensing devices. (4) Developing flexible and wearable power supply systems that can provide sufficient and stable energy for the sensors. (5) Optimizing the fabrication methods and scaling up the production of polymer-based pressure sensors for practical applications. (6) Enhancing reliability and durability under various environmental circumstances.

2. Parameters for Pressure Sensors

Pressure sensors with different operating principles have different sensitivity, stability, linear response range, detect limit, response time and output signals for different types of pressure (absolute, gauge, differential, or vacuum pressure). Therefore, when selecting flexible pressure sensors, appropriate pressure types and operating principles should be selected according to specific application scenarios and test objectives.

2.1. Pressure Sensitivity

The sensitivity (S) is expressed as the change in output signal relative to applied pressure, which is defined as S = (ΔE/E0)/ΔP. The initial electrical signal (such as current, capacitance, voltage, etc.) is denoted by E0, the relative variation of the corresponding signal is denoted by ΔE, and the change of the applied pressure is denoted by ΔP. Generally, sensitivity can be enhanced by decreasing the initial electrical signal E0. The relative variation in voltage output (current, capacitance) on the basis of external pressure is usually indicated, with the slope of the curve representing sensitivity.

2.2. Linear Response Range

The linear response range refers to the range where the output is proportional to the input. In order to ensure a certain level of measurement accuracy, it is highly desirable for the relationship between the external stimuli input and relative electrical signal outputs to be linear. Theoretically, flexible pressure sensors have ideal linear models over a wide range of sensing, but in practice, the linear range is often only a part of the full range.

2.3. Detection Limit and Response Speed

The detection limit and response speed are crucial parameters that determine the effectiveness of a sensor. The detection limit refers to the minimum signal or the corresponding physical quantity that the sensor can measure with a certain precision or repeatability and is used to evaluate whether it is suitable for a given application. The response speed is how fast a sensor reacts to pressure changes. Real-time detection of stimuli signals such as heartbeat pulse, subtle human movements, and gas concentration necessitates a high response speed. In addition, when analyzing the parameter of response time, appropriate research methods should be selected according to different application scenarios and test purposes. If you only observe the response of a slow indicator, you do not need to change the pressure frequently. However, if you study the response of a precision tester, you have to consider the speed and accuracy of the testing equipment itself. Therefore, appropriate research methods must be considered when selecting sensors for these applications.

2.4. Reliability

The reliability of a pressure sensor refers to the ability of its components and equipment to maintain the same function and performance within a specified period of time. The higher the reliability of the sensor, the more stable and accurate it can measure pressure, and it can maintain its performance over a long period of use. In the application areas where the demand for sustained stability is not as high, as long as it is within the margin of error. In other high-reliability demanding applications, such as automotive, industrial automation, and aerospace, the reliability of pressure sensors is crucial because any failure can lead to loss or safety issues.

This entry is adapted from the peer-reviewed paper 10.3390/polym15092176

References

  1. Hu, H.; Zhang, C.; Pan, C.; Dai, H.; Sun, H.; Pan, Y.; Lai, X.; Lyu, C.; Tang, D.; Fu, J.; et al. Wireless Flexible Magnetic Tactile Sensor with Super-Resolution in Large-Areas. ACS Nano 2022, 16, 19271–19280.
  2. Sim, M.; Lee, K.H.; Jeong, Y.; Shin, J.H.; Sohn, J.I.; Cha, S.N.; Jang, J.E. Structural Solution to Enhance the Sensitivity of a Self-Powered Pressure Sensor for an Artificial Tactile System. IEEE Trans. NanoBioscience 2016, 15, 804–811.
  3. Ramadoss, T.S.; Ishii, Y.; Chinnappan, A.; Ang, M.H.; Ramakrishna, S. Fabrication of Pressure Sensor Using Electrospinning Method for Robotic Tactile Sensing Application. Nanomaterials 2021, 11, 1320.
  4. Kim, S.-R.; Lee, S.; Park, J.-W. A Skin-Inspired, Self-Powered Tactile Sensor. Nano Energy 2022, 101, 107608.
  5. Wang, H.; Cheng, J.; Wang, Z.; Ji, L.; Wang, Z.L. Triboelectric Nanogenerators for Human-Health Care. Sci. Bull. 2021, 66, 490–511.
  6. Oh, Y.S.; Kim, J.-H.; Xie, Z.; Cho, S.; Han, H.; Jeon, S.W.; Park, M.; Namkoong, M.; Avila, R.; Song, Z.; et al. Battery-Free, Wireless Soft Sensors for Continuous Multi-Site Measurements of Pressure and Temperature from Patients at Risk for Pressure Injuries. Nat. Commun. 2021, 12, 5008.
  7. Sun, Q.; Lai, Q.; Tang, Z.; Tang, X.; Zhao, X.; Roy, V.A.L. Advanced Functional Composite Materials toward E-Skin for Health Monitoring and Artificial Intelligence. Adv. Mater. Technol. 2023, 8, 2201088.
  8. Lai, Q.; Zhao, X.; Sun, Q.; Tang, Z.; Tang, X.; Roy, V.A.L. Emerging MXene-Based Flexible Tactile Sensors for Health Monitoring and Haptic Perception. Small 2023, 2300283.
  9. Sharma, S.; Chhetry, A.; Sharifuzzaman, M.; Yoon, H.; Park, J.Y. Wearable Capacitive Pressure Sensor Based on MXene Composite Nanofibrous Scaffolds for Reliable Human Physiological Signal Acquisition. ACS Appl. Mater. Interfaces 2020, 12, 22212–22224.
  10. Yu, J.; Hou, X.; Cui, M.; Zhang, S.; He, J.; Geng, W.; Mu, J.; Chou, X. Highly Skin-Conformal Wearable Tactile Sensor Based on Piezoelectric-Enhanced Triboelectric Nanogenerator. Nano Energy 2019, 64, 103923.
  11. Wang, H.; Li, Z.; Liu, Z.; Fu, J.; Shan, T.; Yang, X.; Lei, Q.; Yang, Y.; Li, D. Flexible Capacitive Pressure Sensors for Wearable Electronics. J. Mater. Chem. C 2022, 10, 1594–1605.
  12. Chen, S.; Huang, T.; Zuo, H.; Qian, S.; Guo, Y.; Sun, L.; Lei, D.; Wu, Q.; Zhu, B.; He, C.; et al. A Single Integrated 3D-Printing Process Customizes Elastic and Sustainable Triboelectric Nanogenerators for Wearable Electronics. Adv. Funct. Mater. 2018, 28, 1805108.
  13. Lai, Q.-T.; Sun, Q.-J.; Tang, Z.; Tang, X.-G.; Zhao, X.-H. Conjugated Polymer-Based Nanocomposites for Pressure Sensors. Molecules 2023, 28, 1627.
  14. Chen, B.; Zhang, L.; Li, H.; Lai, X.; Zeng, X. Skin-Inspired Flexible and High-Performance Piezoresistive Pressure Sensor for Human Motion Detection. J. Colloid Interface Sci. 2022, 617, 478–488.
  15. Chun, J.; Kang, N.-R.; Kim, J.-Y.; Noh, M.-S.; Kang, C.-Y.; Choi, D.; Kim, S.-W.; Lin Wang, Z.; Min Baik, J. Highly Anisotropic Power Generation in Piezoelectric Hemispheres Composed Stretchable Composite Film for Self-Powered Motion Sensor. Nano Energy 2015, 11, 1–10.
  16. Huang, C.-Y.; Yang, G.; Huang, P.; Hu, J.-M.; Tang, Z.-H.; Li, Y.-Q.; Fu, S.-Y. Flexible Pressure Sensor with an Excellent Linear Response in a Broad Detection Range for Human Motion Monitoring. ACS Appl. Mater. Interfaces 2023, 15, 3476–3485.
  17. Huang, X.; He, J.; Zhang, L.; Yang, F.; Zhang, D. A Novel Pressure Sensor Design for Low Pressure Ranges. In Proceedings of the 2014 IEEE International Conference on Electron Devices and Solid-State Circuits, Chengdu, China, 18–20 June 2014; pp. 1–2.
  18. Xu, T.; Wang, H.; Xia, Y.; Zhao, Z.; Huang, M.; Wang, J.; Zhao, L.; Zhao, Y.; Jiang, Z. Piezoresistive Pressure Sensor with High Sensitivity for Medical Application Using Peninsula-Island Structure. Front. Mech. Eng. 2017, 12, 546–553.
  19. Basov, M.; Prigodskiy, D. Development of High-Sensitivity Piezoresistive Pressure Sensors for −0.5…+0.5 KPa. J. Micromechanics Microengineering 2020, 30, 105006.
  20. Basov, M. Pressure Sensor with Novel Electrical Circuit Utilizing Bipolar Junction Transistor. In Proceedings of the 2021 IEEE Sensors, Sydney, Australia, 31 October–4 November 2021; pp. 1–4.
  21. Basov, M. Ultra-High Sensitivity MEMS Pressure Sensor Utilizing Bipolar Junction Transistor for Pressures Ranging From −1 to 1 KPa. IEEE Sens. J. 2021, 21, 4357–4364.
  22. Ruth, S.R.A.; Beker, L.; Tran, H.; Feig, V.R.; Matsuhisa, N.; Bao, Z. Rational Design of Capacitive Pressure Sensors Based on Pyramidal Microstructures for Specialized Monitoring of Biosignals. Adv. Funct. Mater. 2020, 30, 1903100.
  23. Yang, J.C.; Kim, J.-O.; Oh, J.; Kwon, S.Y.; Sim, J.Y.; Kim, D.W.; Choi, H.B.; Park, S. Microstructured Porous Pyramid-Based Ultrahigh Sensitive Pressure Sensor Insensitive to Strain and Temperature. ACS Appl. Mater. Interfaces 2019, 11, 19472–19480.
  24. Wang, X.; Zhu, B.; Huang, Y.; Shen, L.; Chai, Y.; Han, J.; Yu, J.; Wang, Z.; Chen, X. High-Performance Self-Powered Integrated System of Pressure Sensor and Supercapacitor Based on /Graphitic Carbon Layered Porous Structure. J. Colloid Interface Sci. 2023, 632, 140–150.
  25. Song, Z.; Liu, Z.; Zhao, L.; Chang, C.; An, W.; Zheng, H.; Yu, S. Biodegradable and Flexible Capacitive Pressure Sensor for Electronic Skins. Org. Electron. 2022, 106, 106539.
  26. Fu, X.; Zhang, J.; Xiao, J.; Kang, Y.; Yu, L.; Jiang, C.; Pan, Y.; Dong, H.; Gao, S.; Wang, Y. A High-Resolution, Ultrabroad-Range and Sensitive Capacitive Tactile Sensor Based on a CNT/PDMS Composite for Robotic Hands. Nanoscale 2021, 13, 18780–18788.
  27. Zhu, M.; Yue, Y.; Cheng, Y.; Zhang, Y.; Su, J.; Long, F.; Jiang, X.; Ma, Y.; Gao, Y. Hollow MXene Sphere/Reduced Graphene Aerogel Composites for Piezoresistive Sensor with Ultra-High Sensitivity. Adv. Electron. Mater. 2020, 6, 1901064.
  28. Karipoth, P.; Pullanchiyodan, A.; Christou, A.; Dahiya, R. Graphite-Based Bioinspired Piezoresistive Soft Strain Sensors with Performance Optimized for Low Strain Values. ACS Appl. Mater. Interfaces 2021, 13, 61610–61619.
  29. Wang, L.; Xia, M.; Wang, D.; Yan, J.; Huang, X.; Luo, J.; Xue, H.-G.; Gao, J. Bioinspired Superhydrophobic and Durable Octadecanoic Acid/Ag Nanoparticle-Decorated Rubber Composites for High-Performance Strain Sensors. ACS Sustain. Chem. Eng. 2021, 9, 7245–7254.
  30. Cao, X.; Zhang, J.; Chen, S.; Varley, R.J.; Pan, K. 1D/2D Nanomaterials Synergistic, Compressible, and Response Rapidly 3D Graphene Aerogel for Piezoresistive Sensor. Adv. Funct. Mater. 2020, 30, 2003618.
  31. Wang, Z.; Liu, Z.; Zhao, G.; Zhang, Z.; Zhao, X.; Wan, X.; Zhang, Y.; Wang, Z.L.; Li, L. Stretchable Unsymmetrical Piezoelectric BaTiO3 Composite Hydrogel for Triboelectric Nanogenerators and Multimodal Sensors. ACS Nano 2022, 16, 1661–1670.
  32. Waseem, A.; Johar, M.A.; Hassan, M.A.; Bagal, I.V.; Abdullah, A.; Ha, J.-S.; Lee, J.K.; Ryu, S.-W. Flexible Self-Powered Piezoelectric Pressure Sensor Based on GaN/p-GaN Coaxial Nanowires. J. Alloy. Compd. 2021, 872, 159661.
  33. Liu, Y.; Lu, G.; Guo, L.; Zhang, Y.; Chen, M. Flexible Pressure Sensor Based on Tetrapod-Shaped ZnO-PDMS Piezoelectric Nanocomposites. IEEE Sens. J. 2023, 23, 3532–3540.
  34. Choudhry, I.; Khalid, H.R.; Lee, H.K.; Lee, H.-K. Flexible Piezoelectric Transducers for Energy Harvesting and Sensing from Human Kinematics. ACS Sustain. Chem. Eng. 2020, 2, 3346–3357.
  35. Su, H.; Wang, X.; Li, C.; Wang, Z.; Wu, Y.; Zhang, J.; Zhang, Y.; Zhao, C.; Wu, J.; Zheng, H. Enhanced Energy Harvesting Ability of Polydimethylsiloxane-BaTiO3-Based Flexible Piezoelectric Nanogenerator for Tactile Imitation Application. Nano Energy 2021, 83, 105809.
  36. Fan, F.-R.; Lin, L.; Zhu, G.; Wu, W.; Zhang, R.; Wang, Z.L. Transparent Triboelectric Nanogenerators and Self-Powered Pressure Sensors Based on Micropatterned Plastic Films. Nano Lett. 2012, 12, 3109–3114.
  37. Sun, Q.-J.; Lei, Y.; Zhao, X.-H.; Han, J.; Cao, R.; Zhang, J.; Wu, W.; Heidari, H.; Li, W.-J.; Sun, Q.; et al. Scalable Fabrication of Hierarchically Structured Graphite/Polydimethylsiloxane Composite Films for Large-Area Triboelectric Nanogenerators and Self-Powered Tactile Sensing. Nano Energy 2021, 80, 105521.
  38. Nawaz, S.M.; Saha, M.; Sepay, N.; Mallik, A. Energy-from-Waste: A Triboelectric Nanogenerator Fabricated from Waste Polystyrene for Energy Harvesting and Self-Powered Sensor. Nano Energy 2022, 104, 107902.
  39. Ding, Z.; Zou, M.; Yao, P.; Fan, L. A Triboelectric Nanogenerator for Mechanical Energy Harvesting and as Self-Powered Pressure Sensor. Microelectron. Eng. 2022, 257, 111725.
  40. Fan, J.-C.; Tang, X.-G.; Sun, Q.-J.; Jiang, Y.-P.; Li, W.-H.; Liu, Q.-X. Low-Cost Composite Film Triboelectric Nanogenerators for a Self-Powered Touch Sensor. Nanoscale 2023.
  41. Zhao, X.; Zhou, Y.; Xu, J.; Chen, G.; Fang, Y.; Tat, T.; Xiao, X.; Song, Y.; Li, S.; Chen, J. Soft Fibers with Magnetoelasticity for Wearable Electronics. Nat. Commun. 2021, 12, 6755.
  42. Zhou, Y.; Zhao, X.; Xu, J.; Fang, Y.; Chen, G.; Song, Y.; Li, S.; Chen, J. Giant Magnetoelastic Effect in Soft Systems for Bioelectronics. Nat. Mater. 2021, 20, 1670–1676.
  43. Chen, G.; Zhao, X.; Andalib, S.; Xu, J.; Zhou, Y.; Tat, T.; Lin, K.; Chen, J. Discovering Giant Magnetoelasticity in Soft Matter for Electronic Textiles. Matter 2021, 4, 3725–3740.
More
© Text is available under the terms and conditions of the Creative Commons Attribution (CC BY) license; additional terms may apply. By using this site, you agree to the Terms and Conditions and Privacy Policy.
This entry is offline, you can click here to edit this entry!
ScholarVision Creations
Feedback