۱- Introduction

۲- Pressure-sensing principles

۳- Recent advances in micro/nanoscale pressure sensors

۴- Conclusions

References

Abstract

Small-sized, low-cost, and high-sensitivity sensors are required for pressure-sensing applications because of their critical role in consumer electronics, automotive applications, and industrial environments. Thus, micro/nanoscale pressure sensors based on micro/nanofabrication and micro/nanoelectromechanical system technologies have emerged as a promising class of pressure sensors on account of their remarkable miniaturization and performance. These sensors have recently been developed to feature multifunctionality and applicability to novel scenarios, such as smart wearable devices and health monitoring systems. In this review, we summarize the major sensing principles used in micro/nanoscale pressure sensors and discuss recent progress in the development of four major categories of these sensors, namely, novel material-based, flexible, implantable, and self-powered pressure sensors.

Introduction

A pressure sensor is a transducer that converts an external pressure stimulus into an electrical or other identifiable output signal according to certain rules.1 Over the last several decades, the role of pressure sensing in daily life has escalated, leading to the rapid growth of its market size. According to a recent study, the global market for pressure sensors is expected to increase to $15.97 billion by the year 2028 from $8.8 billion in 2018. The major pressure-sensor suppliers in the global market include Bosch, Denso, Sensata, and Amphenol. Conventional pressure-sensing devices are mainly based on macroscale diaphragm configurations, the deformation of which indicates the applied pressure. Such sensors provide the advantages of high stability and large dynamic range, but their bulky size limits their further application. Given rapid developments in micro/nanofabrication and micro/nanoelectromechanical system (M/NEMS) technologies, micro/nanoscale pressure sensors based on various measurement principles, e.g., piezoresistive, capacitive, piezoelectric, and resonant transduction,2–۶ have received increased research attention. CMOS compatibility and wafer-scale fabrication have enabled the development of a new generation of pressure sensors with high sensitivity, low cost, and small size to address the needs of current applications.