Highly Sensitive Capacitive Pressure Sensor Based on a Micropyramid Array for Health and Motion Monitoring

Abstract

Flexible capacitive pressure sensors with simple structure and low power consumption have attracted great interest because of their promising applications in wearable electronics. However, assembling a pressure sensor with high sensitivity, low detection limit, and wide dynamic range is still a big challenge. Here, a sandwich‐like, flexible capacitive pressure sensor is reported with micropyramid array electrode and porous dielectric layer. Under external stimulus pressure, the distance between two electrodes, and dielectric constant of dielectric layer will change simultaneously, resulting in high sensitivity (2.51 kPa−1) of the sensor. Due to the micropyramid array electrode, the sensor exhibits low detection limit (2.0 Pa), fast response speed (84 ms), wide working range (>10 kPa), and high stability (>5000 dynamic cycles). Finite‐element analysis also reveals that the larger duty ratio and altitude of micropyramid arrays lead to higher sensor sensitivity. By depicting the deformation of micropyramid during compression, the sensing mechanism of these sensors is discovered, providing a potential direction for developing sensitivity and linear range. Additionally, the sensor has been demonstrated to be efficient in monitoring human motion, such as muscle activation and rope skipping, showing high potential in the field of sport wearable equipment.

Ultrareproducible Capacitive Soft Pressure Sensor Using a Self‐Integrated Fibrous Network of Urethane Equipped with Diels–Alder Adducts

“…Finally, we compared the performance of the developed capacitive pressure sensor with those of recently reported sensors (Table 1). [39][40][41][42] As can be confirmed, the sensitivity and applicable strain range of our sensor had high competitiveness. In addition, considering the reversible crosslinking characteristics of the RCU polymer, the potential application to future self-healable pressure sensor development is also an advantage of this study.…”

Micromachined Tactile Sensor Array for RTSA

“…The response speed of the sensor can be greatly improved by modifying the dielectric layer and surface area of the electrodes. Utilizing carbon nanotube electrodes fabricated with microstructures such as a micro pyramid array increases the sensors sensitivity, response speed, and offers high recoverability and stability [28,29]. Furthermore, altering the overlapping area between the top and bottom electrodes can enable normal and shear stress measurements [30].…”

Soft Iontronic Capacitive Sensor for Beat‐to‐Beat Blood Pressure Measurements

“…In comparison with other capacitive sensors' sensitivity and dynamic ranges, our sensor had high and linear sensitivity over a broad dynamic range (Figure 2b). [44,47,48,54,55,[60][61][62][63][64][65][66][67][68][69] This large dynamic range suits our purposes well where applanation pressure (roughly 23 kPa for radial artery) is applied; here, the sensor still operated in the dynamic range with the highest sensitivity despite the applanation pressure. The entire sensitivity curves obtained from different frequencies were shown in Figure S2 (Supporting Information).…”