High-Linearity Flexible Pressure Sensor Based on the Gaussian-Curve-Shaped Microstructure for Human Physiological Signal Monitoring

Abstract

Flexible pressure sensors with high-performance show broad application prospects in health monitoring, wearable electronic devices, intelligent robot sensing, and other fields. Although flexible pressure sensors have made significant progress in sensitivity and detection range, most of them still exhibit strong nonlinearity, which leads to significant troubles in signal acquisition and thus limits their popularity in practical applications. It remains a serious challenge for the flexible pressure sensor to achieve high linearity while maintaining high sensitivity. Herein, a doped sensing membrane with a uniformly distributed Gaussian-curve-shaped micropattern array was developed using the micro-electromechanical systems (MEMS) process, and a flexible sensor structure with the doped film as the core was designed and constructed. The prototype sensor has a high sensitivity of 1.77 kPa −1 and a linearity of 0.99 in the full detection range of 20 Pa to 30 kPa. In addition, its excellent performance also includes fast response/recovery times (∼25/50 ms) and long-term endurance (>10,000 cycles at 15 kPa). The prototype sensor has been successfully demonstrated in human pulse monitoring, speech recognition, and gesture recognition. The 2 × 6 sensor array can detect the spatial pressure distribution. Thus, such a microstructure shape design will open a new way to fabricate a high-linearity pressure sensor for potential applications in health monitoring, human−machine interaction, etc.

Improving the Resolution of Flexible Large-Area Tactile Sensors through Machine-Learning Perception

“…Inspired by human skin, more and more researchers are working to prepare flexible tactile arrays with skin-like functionality to meet the needs of robotic mechanical claw grip state sensing − and have achieved perception capabilities far beyond skin. − Over the past decade, tactile array sensors have been extensively developed by utilizing different sensing mechanisms, such as resistive-, − capacitive-, − and piezoelectric-type mechanisms. − Among them, piezoresistive tactile sensors have become a focus of research due to their high load capacity, low mass production cost, low noise, and high tactile sensitivity. − Recently, advances in various functional materials, − structural designs, ,− fabrication methods, − and signal processing technologies − have further accelerated the development of tactile array sensors, which now enable pressure detection beyond the limits of the skin and ultrawide pressure monitoring ranges. However, some inherent characteristics of array-type tactile sensors limit their application in practical applications.…”

High-Sensitivity Wearable Flexible Pressure Sensor Based on MXene and Polyaniline for Human Motion Detection

“…19−21 By designing the structure, the pressure sensor has the characteristic of deformation under micro pressure, which not only helps to improve the sensitivity of the sensor but also expands , and successfully applied it to human pulse monitoring, speech recognition, and gesture recognition. 22 However, microstructure design mostly uses laser engraving, 23 3D printing, 24 or inkjet printing, 25 resulting in complex and expensive preparation processes. In contrast, simple, economical, and mass-produced high-sensitivity sensor preparation methods have more advantages.…”

“…In addition, microstructure design, such as micro pyramid arrays, fracture microstructures, and interlocking microstructures, is often considered an effective strategy for manufacturing highly sensitive pressure sensors. − By designing the structure, the pressure sensor has the characteristic of deformation under micro pressure, which not only helps to improve the sensitivity of the sensor but also expands its detection ability under micro pressure. Zhu et al designed a doped sensing film with a uniformly distributed Gaussian curve-shaped micropattern array, constructed a flexible pressure sensor with high sensitivity (1.77 kPa –1 ), and successfully applied it to human pulse monitoring, speech recognition, and gesture recognition . However, microstructure design mostly uses laser engraving, 3D printing, or inkjet printing, resulting in complex and expensive preparation processes.…”

Multi-Level Pyramidal Microstructure-Based Pressure Sensors with High Sensitivity and Wide Linear Range for Healthcare Monitoring

“…Flexible pressure sensors can convert mechanical stimuli into electrical signals for applications such as wearable health detection and robotic electronic skins. , Compared to capacitive sensors , and piezoelectric sensors, , piezoresistive sensors have garnered significant attention owing to their simple and stable signal output, simple structure, and low cost. , Although considerable progress has been made in the sensitivity, detection limits, flexibility and stability of existing flexible pressure sensors, high sensitivity, and wide linear detection range need to be combined in practical application scenarios . High sensitivity allows sensors to easily distinguish subtle pressure stimulation, − wide detection range allows sensors to distinguish low and high pressures without the need to change sensors with different ranges, and linear signal allows input pressure signals to be easily calculated as corresponding electrical output signals …”