Ultrahigh Sensitivity Micro-cliff Graphene Wearable Pressure Sensor Made by Instant Flash Light Exposure

For wearable health monitoring systems and soft robotics, stretchable/flexible pressure sensors have continuously drawn attention owing to a wide range of potential applications such as the detection of human physiological and activity signals, and electronic skin (e-skin). Here, we demonstrated a highly stretchable pressure sensor using silver nanowires (AgNWs) and photo-patternable polyurethane acrylate (PUA). In particular, the characteristics of the pressure sensors could be moderately controlled through a micro-patterned hole structure in the PUA spacer and size-designs of the patterned hole area. With the structural-tuning strategies, adequate control of the site-specific sensitivity in the range of 47~83 kPa−1 and in the sensing range from 0.1 to 20 kPa was achieved. Moreover, stacked AgNW/PUA/AgNW (APA) structural designed pressure sensors with mixed hole sizes of 10/200 µm and spacer thickness of 800 µm exhibited high sensitivity (~171.5 kPa−1) in the pressure sensing range of 0~20 kPa, fast response (100~110 ms), and high stretchability (40%). From the results, we envision that the effective structural-tuning strategy capable of controlling the sensing properties of the APA pressure sensor would be employed in a large-area stretchable pressure sensor system, which needs site-specific sensing properties, providing monolithic implementation by simply arranging appropriate micro-patterned hole architectures.

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Flexible and Highly Sensitive Pressure Sensors Based on Microstructured Carbon Nanowalls Electrodes

Nanomaterials ◽

10.3390/nano9040496 ◽

2019 ◽

Vol 9 (4) ◽

pp. 496 ◽

Cited By ~ 10

Author(s):

Xi Zhou ◽

Yongna Zhang ◽

Jun Yang ◽

Jialu Li ◽

Shi Luo ◽

...

Keyword(s):

Pressure Sensor ◽

High Performance ◽

Limit Of Detection ◽

Pressure Sensors ◽

High Sensitivity ◽

Physiological Signals ◽

Healthcare Applications ◽

Highly Sensitive ◽

Carbon Nanowalls ◽

Pressure Regime

Wearable pressure sensors have attracted widespread attention in recent years because of their great potential in human healthcare applications such as physiological signals monitoring. A desirable pressure sensor should possess the advantages of high sensitivity, a simple manufacturing process, and good stability. Here, we present a highly sensitive, simply fabricated wearable resistive pressure sensor based on three-dimensional microstructured carbon nanowalls (CNWs) embedded in a polydimethylsiloxane (PDMS) substrate. The method of using unpolished silicon wafers as templates provides an easy approach to fabricate the irregular microstructure of CNWs/PDMS electrodes, which plays a significant role in increasing the sensitivity and stability of resistive pressure sensors. The sensitivity of the CNWs/PDMS pressure sensor with irregular microstructures is as high as 6.64 kPa−1 in the low-pressure regime, and remains fairly high (0.15 kPa−1) in the high-pressure regime (~10 kPa). Both the relatively short response time of ~30 ms and good reproducibility over 1000 cycles of pressure loading and unloading tests illustrate the high performance of the proposed device. Our pressure sensor exhibits a superior minimal limit of detection of 0.6 Pa, which shows promising potential in detecting human physiological signals such as heart rate. Moreover, it can be turned into an 8 × 8 pixels array to map spatial pressure distribution and realize array sensing imaging.

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Flexible and highly sensitive pressure sensors based on microcrack arrays inspired by scorpions

RSC Advances ◽

10.1039/c9ra03663f ◽

2019 ◽

Vol 9 (39) ◽

pp. 22740-22748

Author(s):

Junqiu Zhang ◽

Tao Sun ◽

Linpeng Liu ◽

Shichao Niu ◽

Kejun Wang ◽

...

Keyword(s):

Pressure Sensor ◽

Pressure Sensors ◽

Highly Sensitive ◽

Sensitive Pressure

The pressure sensor based on microcrack arrays inspired by the scorpion.

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A Soft Pressure Sensor Array Based on a Conducting Nanomembrane

Micromachines ◽

10.3390/mi12080933 ◽

2021 ◽

Vol 12 (8) ◽

pp. 933

Author(s):

Daekwang Jung ◽

Kyumin Kang ◽

Hyunjin Jung ◽

Duhwan Seong ◽

Soojung An ◽

...

Keyword(s):

Pressure Sensor ◽

High Performance ◽

Sensor Array ◽

Pressure Sensors ◽

Strain Range ◽

High Sensitivity ◽

Critical Issue ◽

Mechanical Stimuli ◽

Highly Sensitive ◽

Accumulated Strain

Although skin-like pressure sensors exhibit high sensitivity with a high performance over a wide area, they have limitations owing to the critical issue of being linear only in a narrow strain range. Various strategies have been proposed to improve the performance of soft pressure sensors, but such a nonlinearity issue still exists and the sensors are only effective within a very narrow strain range. Herein, we fabricated a highly sensitive multi-channel pressure sensor array by using a simple thermal evaporation process of conducting nanomembranes onto a stretchable substrate. A rigid-island structure capable of dissipating accumulated strain energy induced by external mechanical stimuli was adopted for the sensor. The performance of the sensor was precisely controlled by optimizing the thickness of the stretchable substrate and the number of serpentines of an Au membrane. The fabricated sensor exhibited a sensitivity of 0.675 kPa−1 in the broad pressure range of 2.3–50 kPa with linearity (~0.990), and good stability (>300 Cycles). Finally, we successfully demonstrated a mapping of pressure distribution.

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Sea urchin-like microstructure pressure sensors with an ultra-broad range and high sensitivity

Nature Communications ◽

10.1038/s41467-021-21958-y ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Xiu-man Wang ◽

Lu-qi Tao ◽

Min Yuan ◽

Ze-ping Wang ◽

Jiabing Yu ◽

...

Keyword(s):

Sea Urchin ◽

Pressure Sensor ◽

Pressure Range ◽

Synergistic Effects ◽

Pressure Sensors ◽

High Sensitivity ◽

Fast Response ◽

Carbon Layer ◽

Single Structure ◽

Wide Pressure Range

AbstractSensitivity and pressure range are two significant parameters of pressure sensors. Existing pressure sensors have difficulty achieving both high sensitivity and a wide pressure range. Therefore, we propose a new pressure sensor with a ternary nanocomposite Fe2O3/C@SnO2. The sea urchin-like Fe2O3 structure promotes signal transduction and protects Fe2O3 needles from mechanical breaking, while the acetylene carbon black improves the conductivity of Fe2O3. Moreover, one part of the SnO2 nanoparticles adheres to the surfaces of Fe2O3 needles and forms Fe2O3/SnO2 heterostructures, while its other part disperses into the carbon layer to form SnO2@C structure. Collectively, the synergistic effects of the three structures (Fe2O3/C, Fe2O3/SnO2 and SnO2@C) improves on the limited pressure response range of a single structure. The experimental results demonstrate that the Fe2O3/C@SnO2 pressure sensor exhibits high sensitivity (680 kPa−1), fast response (10 ms), broad range (up to 150 kPa), and good reproducibility (over 3500 cycles under a pressure of 110 kPa), implying that the new pressure sensor has wide application prospects especially in wearable electronic devices and health monitoring.

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A new strategy for the fabrication of a flexible and highly sensitive capacitive pressure sensor

Microsystems & Nanoengineering ◽

10.1038/s41378-021-00327-1 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Ruzhan Qin ◽

Mingjun Hu ◽

Xin Li ◽

Te Liang ◽

Haoyi Tan ◽

...

Keyword(s):

Pressure Sensor ◽

Pressure Sensors ◽

High Sensitivity ◽

Capacitive Sensor ◽

Capacitive Pressure Sensor ◽

Interdigital Electrode ◽

Interdigital Electrodes ◽

Highly Sensitive ◽

New Strategy ◽

Application Prospects

AbstractThe development of flexible capacitive pressure sensors has wide application prospects in the fields of electronic skin and intelligent wearable electronic devices, but it is still a great challenge to fabricate capacitive sensors with high sensitivity. Few reports have considered the use of interdigital electrode structures to improve the sensitivity of capacitive pressure sensors. In this work, a new strategy for the fabrication of a high-performance capacitive flexible pressure sensor based on MXene/polyvinylpyrrolidone (PVP) by an interdigital electrode is reported. By increasing the number of interdigital electrodes and selecting the appropriate dielectric layer, the sensitivity of the capacitive sensor can be improved. The capacitive sensor based on MXene/PVP here has a high sensitivity (~1.25 kPa−1), low detection limit (~0.6 Pa), wide sensing range (up to 294 kPa), fast response and recovery times (~30/15 ms) and mechanical stability of 10000 cycles. The presented sensor here can be used for various pressure detection applications, such as finger pressing, wrist pulse measuring, breathing, swallowing and speech recognition. This work provides a new method of using interdigital electrodes to fabricate a highly sensitive capacitive sensor with very promising application prospects in flexible sensors and wearable electronics.

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A Flexible and Highly Sensitive Inductive Pressure Sensor Array Based on Ferrite Films

Sensors ◽

10.3390/s19102406 ◽

2019 ◽

Vol 19 (10) ◽

pp. 2406 ◽

Cited By ~ 11

Author(s):

Xinran Tang ◽

Yihui Miao ◽

Xinjian Chen ◽

Baoqing Nie

Keyword(s):

Pressure Sensor ◽

Sensor Array ◽

Pressure Sensors ◽

Separation Distance ◽

Spiral Inductor ◽

Ferrite Film ◽

Wearable Electronics ◽

Highly Sensitive ◽

Ultrahigh Sensitivity ◽

Inductive Pressure

There is a rapid growing demand for highly sensitive, easy adaptive and low-cost pressure sensing solutions in the fields of health monitoring, wearable electronics and home care. Here, we report a novel flexible inductive pressure sensor array with ultrahigh sensitivity and a simple construction, for large-area contact pressure measurements. In general, the device consists of three layers: a planar spiral inductor layer and ferrite film units attached on a polyethylene terephthalate (PET) membrane, which are separated by an array of elastic pillars. Importantly, by introducing the ferrite film with an excellent magnetic permeability, the effective permeability around the inductor is greatly influenced by the separation distance between the inductor and the ferrite film. As a result, the value of the inductance changes largely as the separation distance varies as an external load applies. Our device has achieved an ultrahigh sensitivity of 1.60 kPa−1 with a resolution of 13.61 Pa in the pressure range of 0–0.18 kPa, which is comparable to the current state-of-the-art flexible pressure sensors. More remarkably, our device shows an outstanding stability when exposed to environmental interferences, e.g., electrical noises from skin surfaces (within 0.08% variations) and a constant pressure load for more than 32 h (within 0.3% variations). In addition, the device exhibits a fast response time of 111 ms and a good repeatability under cyclic pressures varying from 38.45 to 177.82 Pa. To demonstrate its practical usage, we have successfully developed a 4 × 4 inductive pressure sensor array into a wearable keyboard for a smart electronic calendar application.

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Molecule-Graphene Hybrid Materials with Tunable Mechanoresponse: Highly Sensitive Pressure Sensors for Health Monitoring

Advanced Materials ◽

10.1002/adma.201804600 ◽

2018 ◽

Vol 31 (1) ◽

pp. 1804600 ◽

Cited By ~ 47

Author(s):

Chang-Bo Huang ◽

Samanta Witomska ◽

Alessandro Aliprandi ◽

Marc-Antoine Stoeckel ◽

Massimo Bonini ◽

...

Keyword(s):

Hybrid Materials ◽

Health Monitoring ◽

Pressure Sensors ◽

Highly Sensitive ◽

Sensitive Pressure

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Sea Urchin-like Microstructures Pressure Sensors with Ultra-sensitivity and Super Working Range

10.21203/rs.3.rs-75243/v1 ◽

2020 ◽

Author(s):

Xiu Wang ◽

Lu-Qi Tao ◽

Min Yuan ◽

Ze-Ping Wang ◽

Jiabing Yu ◽

...

Keyword(s):

Sea Urchin ◽

Pressure Sensor ◽

Pressure Range ◽

Sno2 Nanoparticles ◽

Pressure Sensors ◽

High Sensitivity ◽

Fast Response ◽

Carbon Layer ◽

Single Structure ◽

Wide Pressure Range

Abstract Sensitivity and pressure range are two significant parameters of pressure sensors. The existing pressure sensors are difficult to achieve both high sensitivity and a wide pressure range. In this regard, we proposed a new pressure sensor with a ternary nanocomposite Fe2O3/C@SnO2. Notably, the sea urchin-like Fe2O3 structure promoted signal transduction and protected Fe2O3 needles from mechanical breaking; while, acetylene carbon black improved the conductivity of Fe2O3. Moreover, one part of SnO2 nanoparticles adhered to the surface of Fe2O3 needles and formed Fe2O3/SnO2 heterostructures whereas its other part of nanoparticles dispersed into the carbon layer and formed SnO2@C structures. Collectively, the synergy of the three structures (Fe2O3/C, Fe2O3/SnO2 and SnO2@C) improved the limited pressure response range of a single structure. The experimental results demonstrated that the Fe2O3/C@SnO2 pressure sensor exhibits high sensitivity (680 kPa-1), fast response (10 ms), broad range (up to 150 kPa), and good reproducibility (over 3500 cycles under a pressure of 110 kPa). This implies that the new pressure sensor has wide application prospects especially in wearable electronic devices and health monitoring.

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