A multiscale flexible pressure sensor based on nanovesicle-like hollow microspheres for micro-vibration detection in non-contact mode

Nanoscale ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 5737-5745 ◽  
Author(s):  
Tie Li ◽  
Lili Li ◽  
Yuanyuan Bai ◽  
Yudong Cao ◽  
Qifeng Lu ◽  
...  
Keyword(s):  
Pressure Sensor ◽  
Pressure Sensors ◽  
Hollow Microspheres ◽  
Contact Mode ◽  
Vibration Signals ◽  
Vibration Detection ◽  
Flexible Pressure Sensor ◽  
Micro Vibration ◽  
Flexible Pressure Sensors

Hierarchical nanovesicle-like hollow microspheres are employed to fabricate flexible pressure sensors for detecting micro-vibration signals in non-contacting mode.

A Full Printed Flexible Pressure Sensor with Improved Temperature Performance based on Optimized Curing Mechanism

2021 ◽  
Author(s):  
Jingnan Ma ◽  
Mengmeng Liang ◽  
Wei Wang
Keyword(s):  
High Temperature ◽  
Pressure Sensor ◽  
Flexible Electronics ◽  
Material Selection ◽  
Pressure Sensors ◽  
Functional Materials ◽  
Temperature Performance ◽  
Curing Mechanism ◽  
Flexible Pressure Sensor ◽  
Flexible Pressure Sensors

Printable flexible pressure sensors have many important applications in wearable systems. One major challenge of such a sensor is to maintain sensing properties in high temperature. By optimizing the curing mechanism of the flexible pressure sensor functional materials, this paper proposes a new method of achieving high temperature properties for a full printed sensor. The establishment of curing theory is mainly studied. The printing process of this kind of sensor is systematically stated and tested to check whether it can continue to function at high temperatures. Ultimately a fully-printed flexible pressure sensor with good temperature performance is achieved. The paper focuses around the technical route of “material selection—theoretical analysis —function material preparation—design and preparation of device—device performance evaluation”. Suitable materials are used in flexible pressure sensors and the curing mechanism is established. This proposed technique can be extended to the development of other printable flexible sensors, which can lead to a huge impact on future applications of the flexible electronics.

scholarly journals Printed and Flexible Capacitive Pressure Sensor with Carbon Nanotubes based Composite Dielectric Layer

Micromachines ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 715 ◽  
Author(s):  
Zhenxin Guo ◽  
Lixin Mo ◽  
Yu Ding ◽  
Qingqing Zhang ◽  
Xiangyou Meng ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Carbon Nanotubes ◽  
Aspect Ratio ◽  
Pressure Sensor ◽  
Dielectric Layer ◽  
Pressure Sensors ◽  
Weight Fraction ◽  
Capacitive Pressure Sensor ◽  
Flexible Pressure Sensor ◽  
Flexible Pressure Sensors

Flexible pressure sensors have attracted tremendous attention from researchers for their widely applications in tactile artificial intelligence, electric skin, disease diagnosis, and healthcare monitoring. Obtaining flexible pressure sensors with high sensitivity in a low cost and convenient way remains a huge challenge. In this paper, the composite dielectric layer based on the mixture of carbon nanotubes (CNTs) with different aspect ratios and polydimethylsiloxane (PDMS) was employed in flexible capacitive pressure sensor to increase its sensitivity. In addition, the screen printing instead of traditional etching based methods was used to prepare the electrodes array of the sensor. The results showed that the aspect ratio and weight fraction of the CNTs play an important role in improving the sensitivity of the printed capacitive pressure sensor. The prepared capacitive sensor with the CNTs/PDMS composite dielectric layer demonstrated a maximum sensitivity of 2.9 kPa−1 in the pressure range of 0–450 Pa, by using the CNTs with an aspect ratio of 1250–3750 and the weight fraction of 3.75%. The mechanism study revealed that the increase of the sensitivity of the pressure sensor should be attributed to the relative permittivity increase of the composite dielectric layer under pressure. Meanwhile, the printed 3 × 3 and 10 × 10 sensor arrays showed excellent spatial resolution and uniformity when they were applied to measure the pressure distribution. For further applications, the flexible pressure sensor was integrated on an adhesive bandage to detect the finger bending, as well as used to create Morse code by knocking the sensor to change their capacitance curves. The printed and flexible pressure sensor in this study might be a good candidate for the development of tactile artificial intelligence, intelligent medical diagnosis systems and wearable electronics.

scholarly journals A Highly Sensitive and Flexible Capacitive Pressure Sensor Based on a Porous Three-Dimensional PDMS/Microsphere Composite

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1412 ◽  
Author(s):  
Young Jung ◽  
Wookjin Lee ◽  
Kyungkuk Jung ◽  
Byunggeon Park ◽  
Jinhyoung Park ◽  
...  
Keyword(s):  
Pressure Sensor ◽  
Sacrificial Layer ◽  
Three Dimensional ◽  
Pressure Sensors ◽  
Capacitive Pressure Sensor ◽  
Mechanical Stimuli ◽  
Highly Sensitive ◽  
Flexible Pressure Sensors ◽  
Fast Rise ◽  
Better Than

In recent times, polymer-based flexible pressure sensors have been attracting a lot of attention because of their various applications. A highly sensitive and flexible sensor is suggested, capable of being attached to the human body, based on a three-dimensional dielectric elastomeric structure of polydimethylsiloxane (PDMS) and microsphere composite. This sensor has maximal porosity due to macropores created by sacrificial layer grains and micropores generated by microspheres pre-mixed with PDMS, allowing it to operate at a wider pressure range (~150 kPa) while maintaining a sensitivity (of 0.124 kPa−1 in a range of 0~15 kPa) better than in previous studies. The maximized pores can cause deformation in the structure, allowing for the detection of small changes in pressure. In addition to exhibiting a fast rise time (~167 ms) and fall time (~117 ms), as well as excellent reproducibility, the fabricated pressure sensor exhibits reliability in its response to repeated mechanical stimuli (2.5 kPa, 1000 cycles). As an application, we develop a wearable device for monitoring repeated tiny motions, such as the pulse on the human neck and swallowing at the Adam’s apple. This sensory device is also used to detect movements in the index finger and to monitor an insole system in real-time.

Flexible hemispheric microarrays of highly pressure-sensitive sensors based on breath figure method

Nanoscale ◽  
2018 ◽  
Vol 10 (22) ◽  
pp. 10691-10698 ◽  
Author(s):  
Zhihui Wang ◽  
Ling Zhang ◽  
Jin Liu ◽  
Hao Jiang ◽  
Chunzhong Li
Keyword(s):  
Pressure Sensor ◽  
Pressure Sensors ◽  
Pressure Sensing ◽  
Sensing Range ◽  
Pressure Sensitive ◽  
Breath Figure ◽  
Breath Figure Method ◽  
Flexible Pressure Sensors

Flexible pressure sensors with interlocked hemispheric microstructures are prepared by a novel breath figure strategy. The subtle microstructure remarkably improves the sensitivity and pressure sensing range of the pressure sensor.

A flexible pressure sensor based on an MXene–textile network structure

2019 ◽  
Vol 7 (4) ◽  
pp. 1022-1027 ◽  
Author(s):  
Tongkuai Li ◽  
Longlong Chen ◽  
Xiang Yang ◽  
Xin Chen ◽  
Zhihan Zhang ◽  
...  
Keyword(s):  
Network Structure ◽  
Pressure Sensor ◽  
High Performance ◽  
Pressure Sensors ◽  
Wearable Electronics ◽  
Physiological Signal ◽  
Signal Perception ◽  
Performance Pressure ◽  
Human Machine Interfaces ◽  
Flexible Pressure Sensor

High-performance pressure sensors have attracted considerable attention recently due to their promising applications in touch displays, wearable electronics, human–machine interfaces, and real-time physiological signal perception.

scholarly journals High-Sensitivity Flexible Pressure Sensor-Based 3D CNTs Sponge for Human–Computer Interaction

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3465
Author(s):  
Jianli Cui ◽  
Xueli Nan ◽  
Guirong Shao ◽  
Huixia Sun
Keyword(s):  
Pressure Sensor ◽  
High Performance ◽  
Large Scale ◽  
Low Cost ◽  
Pressure Sensors ◽  
Chemical Vapor ◽  
High Sensitivity ◽  
Wearable Electronics ◽  
Wide Range ◽  
Flexible Pressure Sensors

Researchers are showing an increasing interest in high-performance flexible pressure sensors owing to their potential uses in wearable electronics, bionic skin, and human–machine interactions, etc. However, the vast majority of these flexible pressure sensors require extensive nano-architectural design, which both complicates their manufacturing and is time-consuming. Thus, a low-cost technology which can be applied on a large scale is highly desirable for the manufacture of flexible pressure-sensitive materials that have a high sensitivity over a wide range of pressures. This work is based on the use of a three-dimensional elastic porous carbon nanotubes (CNTs) sponge as the conductive layer to fabricate a novel flexible piezoresistive sensor. The synthesis of a CNTs sponge was achieved by chemical vapor deposition, the basic underlying principle governing the sensing behavior of the CNTs sponge-based pressure sensor and was illustrated by employing in situ scanning electron microscopy. The CNTs sponge-based sensor has a quick response time of ~105 ms, a high sensitivity extending across a broad pressure range (less than 10 kPa for 809 kPa−1) and possesses an outstanding permanence over 4,000 cycles. Furthermore, a 16-pixel wireless sensor system was designed and a series of applications have been demonstrated. Its potential applications in the visualizing pressure distribution and an example of human–machine communication were also demonstrated.

scholarly journals Flexible Pressure Sensor with Micro-Structure Arrays Based on PDMS and PEDOT:PSS/PUD&CNTs Composite Film with 3D Printing

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6499
Author(s):  
Yiwei Shao ◽  
Qi Zhang ◽  
Yulong Zhao ◽  
Xing Pang ◽  
Mingjie Liu ◽  
...  
Keyword(s):  
3D Printing ◽  
Pressure Sensor ◽  
Pressure Sensors ◽  
Human Motion ◽  
Bottom Plate ◽  
Durability Test ◽  
Printing Technology ◽  
Digital Light Processing ◽  
3D Printing Technology ◽  
Flexible Pressure Sensor

Flexible pressure sensors are widely used in different fields, especially in human motion, robot monitoring and medical treatment. Herein, a flexible pressure sensor consists of the flat top plate, and the microstructured bottom plate is developed. Both plates are made of polydimethylsiloxane (PDMS) by molding from the 3D printed template. The contact surfaces of the top and bottom plates are coated with a mixture of poly (3,4-ethylenedioxythiophene) poly (styrene sulfonate) (PEDOT:PSS) and polyurethane dispersion (PUD) as stretchable film electrodes with carbon nanotubes on the electrode surface. By employing 3D printing technology, using digital light processing (DLP), the fabrication of the sensor is low-cost and fast. The sensor models with different microstructures are first analyzed by the Finite Element Method (FEM), and then the models are fabricated and tested. The sensor with 5 × 5 hemispheres has a sensitivity of 3.54 × 10−3 S/kPa in the range of 0–22.2 kPa. The zero-temperature coefficient is −0.0064%FS/°C. The durability test is carried out for 2000 cycles, and it remains stable during the whole test. This work represents progress in flexible pressure sensing and demonstrates the advantages of 3D printing technology in sensor processing.

scholarly journals Fabrication and Performance of Graphene Flexible Pressure Sensor with Micro/Nano Structure

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7022
Author(s):  
Weibin Wu ◽  
Chongyang Han ◽  
Rongxuan Liang ◽  
Jian Xu ◽  
Bin Li ◽  
...  
Keyword(s):  
Pressure Sensor ◽  
Mass Fraction ◽  
Flexible Substrate ◽  
Conductive Polymer ◽  
Pressure Sensors ◽  
Carbon Paste ◽  
Alloy Plate ◽  
Bionic Structure ◽  
Flexible Pressure Sensor ◽  
Laser Flux

Laser-induced graphene (LIG) has been widely used in flexible sensors due to its excellent mechanical properties and high conductivity. In this paper, a flexible pressure sensor prepared by bionic micro/nanostructure design and LIG mass fraction regulation is reported. First, prepared LIG and conductive carbon paste (CCP) solutions were mixed to obtain a conductive polymer. After the taro leaf structure was etched on the surface of the aluminum alloy plate by Nd:YAG laser processing, the conductive polymer was evenly coated on the template. Pressure sensors were packaged with a stencil transfer printing combined with an Ecoflex flexible substrate. Finally, the effects of different laser flux and the proportion of LIG in the composite on the sensitivity of the sensor are discussed. The results show that when the laser flux is 71.66 J·cm−2 and the mass fraction of LIG is 5%, the sensor has the best response characteristics, with a response time and a recovery time of 86 ms and 101 ms, respectively, with a sensitivity of 1.2 kPa−1 over a pressure range of 0–6 kPa, and stability of 650 cycle tests. The LIG/CCP sensor with a bionic structure demonstrates its potential in wearable devices.

All-transparent graphene-based flexible pressure sensor array

2017 ◽  
Vol 31 (07) ◽  
pp. 1741009 ◽  
Author(s):  
Min Zhang ◽  
Yichuan Wu ◽  
Xudong Wang ◽  
Xiaohao Wang
Keyword(s):  
Human Skin ◽  
Spatial Resolution ◽  
Pressure Sensor ◽  
Sensor Array ◽  
Pressure Sensors ◽  
Tactile Sensor ◽  
Middle Layer ◽  
Tactile Sensor Array ◽  
Flexible Pressure Sensor

In this work, we propose and demonstrate a flexible capacitive tactile sensor array based on graphene served as electrodes. The sensor array consists of 3 × 3 units with 3 mm spatial resolution, similar to that of human skin. Each unit has three layers. The middle layer with microstructured PDMS served as an insulator is sandwiched by two perpendicular graphene-based electrodes. The size of each unit is 3 mm × 3 mm and the initial capacitance is about 0.2 pF. High sensitivities of 0.73 kPa[Formula: see text] between 0 and 1.2 kPa and 0.26 kPa[Formula: see text] between 1.2 and 2.5 kPa were achieved on the fabricated graphene pressure sensors. The proposed flexible pressure sensor array shows a great potential on the application of electric skin or 3D touch control.

scholarly journals Self-Restoring Capacitive Pressure Sensor Based on Three-Dimensional Porous Structure and Shape Memory Polymer

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 824
Author(s):  
Byunggeon Park ◽  
Young Jung ◽  
Jong Soo Ko ◽  
Jinhyoung Park ◽  
Hanchul Cho
Keyword(s):  
Porous Structure ◽  
Shape Memory ◽  
Pressure Sensor ◽  
Shape Memory Polymer ◽  
Three Dimensional ◽  
Pressure Sensors ◽  
Capacitive Pressure Sensor ◽  
Practical Applications ◽  
Flexible Pressure Sensor ◽  
Sensing Performance

Highly flexible and compressible porous polyurethane (PU) structures have effectively been applied in capacitive pressure sensors because of the good elastic properties of the PU structures. However, PU porous structure-based pressure sensors have been limited in practical applications owing to their low durability during pressure cycling. Herein, we report a flexible pressure sensor based on a three-dimensional porous structure with notable durability at a compressive pressure of 500 kPa facilitated by the use of a shape memory polymer (SMP). The SMP porous structure was fabricated using a sugar templating process and capillary effect. The use of the SMP resulted in the maintenance of the sensing performance for 100 cycles at 500 kPa; the SMP can restore its original shape within 30 s of heating at 80 °C. The pressure sensor based on the SMP exhibited a higher sensitivity of 0.0223 kPa−1 than a typical PU-based sensor and displayed excellent sensing performance in terms of stability, response time, and hysteresis. Additionally, the proposed sensor was used to detect shoe insole pressures in real time and exhibited remarkable durability and motion differentiation.

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