Birefringent elastomers with Multiple Stimuli-Responses

2021 ◽  
Author(s):  
Yiyang Gao ◽  
Danqi Sun ◽  
Jing Chen ◽  
Lei Shi ◽  
Xinyu Da ◽  
...  
Keyword(s):  
Strain Sensor ◽  
High Sensitivity ◽  
Soft Materials ◽  
Fast Response ◽  
Optical Devices ◽  
High Birefringence ◽  
Interference Color ◽  
Human Body Temperature ◽  
Low Modulus ◽  
Shed Light

Abstract Currently, even though birefringent soft materials have attracted considerable attention for many sensors and optical devices, it is still difficult for most of them to achieve multiple responses. Herein, we have designed a multiple-responding birefringent elastomer with high birefringence but low modulus by using 2-phenoxy-ethanoacrylate (PHEA) as monomer and 4-cyano-4'pentylbiphenyl as solvent. The excellent transparency (~90%) exhibited by the designed birefringent elastomer allowed us to observe the change of interference color. The obtained birefringent elastomer not only can be used as a photoelastic strain sensor with high sensitivity and fast response but also show a very sensitive response to heat, particularly in the range of the human body temperature. More interestingly, it shows excellent dielectric properties with a strong correlation between the interference color and the applied electric field, which allows easily writing and erasing the encrypted information. These unique multi-signal response features of our obtained birefringent elastomer shed light on the multiple information encryptions, the anti-counterfeiting, and the multifunctional sensors.

Flexible strain sensor with high sensitivity, fast response, and good sensing range for wearable applications

2021 ◽  
Author(s):  
Suresh Nuthalapati ◽  
Vaishakh Kedambaimoole ◽  
Vijay Shirhatti ◽  
Saurabh Kumar ◽  
Hidekuni Takao ◽  
...  
Keyword(s):  
Strain Sensor ◽  
High Sensitivity ◽  
Fast Response ◽  
Sensing Range ◽  
Flexible Strain Sensor

Ti3C2Tx MXene/polyvinyl alcohol decorated polyester warp knitting fabric for flexible wearable strain sensors

2021 ◽  
pp. 004051752110441
Author(s):  
Qinghua Yu ◽  
Jinhua Jiang ◽  
Chuanli Su ◽  
Yaoli Huang ◽  
Nanliang Chen ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Self Assembly ◽  
Low Cost ◽  
Strain Sensor ◽  
High Sensitivity ◽  
Fast Response ◽  
Disease Diagnosis ◽  
Strain Sensors ◽  
Layer By Layer ◽  
Sensing Range

Flexible wearable strain sensors with excellent sensing performance have received widespread interest due to their superior application capability in the field of human-computer interaction, sports rehabilitation, and disease diagnosis. But at present, it is still a considerable challenge to exploit a flexible strain sensor with high sensitivity and wide sensing range that is easily manufactured, low-cost, and easily integrable into clothing. MXene is a promising material sensitive enough for flexible sensors due to its superior conductivity and hydrophilicity. The warp knitting weft insertion textile structure gives the fabric excellent elasticity, making it suitable as a flexible, stretchable substrate. Therefore, utilizing a polyester elastic fabric with a warp knitting weft insertion structure, a fabric strain sensor with high sensitivity and wide sensing range prepared by layer-by-layer self-assembly of polyvinyl alcohol layers and MXene layers is reported in this study. The strain sensor exhibits high sensitivity (up to 288.43), a wide sensing range (up to 50%), fast response time (50 ms), ultra-low detection limit (a strain of 0.067%), excellent cycle stability (1000 cycles), and good washability. Besides, affixing the MXene/polyvinyl alcohol/polyester elastic fabric strain sensor on the joints can detect the movement of limbs. Therefore, the MXene/polyvinyl alcohol/polyester elastic fabric strain sensor demonstrates potential application opportunities in smart wearable electronic devices, and the researcher can also apply this method in the production of other flexible, intelligent wearable devices.

scholarly journals A Sprayed Graphene Pattern-Based Flexible Strain Sensor with High Sensitivity and Fast Response

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1077 ◽  
Author(s):  
Wei Xu ◽  
Tingting Yang ◽  
Feng Qin ◽  
Dongdong Gong ◽  
Yijia Du ◽  
...  
Keyword(s):  
Strain Sensor ◽  
High Sensitivity ◽  
Fast Response ◽  
Strain Sensors ◽  
Biomedical Science ◽  
Gauge Factor ◽  
Experimental Conditions ◽  
Simple Method ◽  
Wide Range ◽  
Flexible Strain Sensor

Flexible strain sensors have a wide range of applications in biomedical science, aerospace industry, portable devices, precise manufacturing, etc. However, the manufacturing processes of most flexible strain sensors previously reported have usually required high manufacturing costs and harsh experimental conditions. Besides, research interests are often focused on improving a single attribute parameter while ignoring others. This work aims to propose a simple method of manufacturing flexible graphene-based strain sensors with high sensitivity and fast response. Firstly, oxygen plasma treats the substrate to improve the interfacial interaction between graphene and the substrate, thereby improving device performance. The graphene solution is then sprayed using a soft PET mask to define a pattern for making the sensitive layer. This flexible strain sensor exhibits high sensitivity (gauge factor ~100 at 1% strain), fast response (response time: 400–700 μs), good stability (1000 cycles), and low overshoot (<5%) as well. Those processes used are compatible with a variety of complexly curved substrates and is expected to broaden the application of flexible strain sensors.

scholarly journals Flexible Metal/Polymer Composite Films Embedded with Silver Nanowires as a Stretchable and Conductive Strain Sensor for Human Motion Monitoring

Micromachines ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 372 ◽  
Author(s):  
Jinjin Luan ◽  
Qing Wang ◽  
Xu Zheng ◽  
Yao Li ◽  
Ning Wang
Keyword(s):  
Polymer Composite ◽  
Silver Nanowires ◽  
Composite Films ◽  
Strain Sensor ◽  
High Sensitivity ◽  
Human Motion ◽  
Applied Strain ◽  
Potential Candidate ◽  
Flexible Metal ◽  
Metal Polymer

To avoid conductive failure due to the cracks of the metal thin film under external loads for the wearable strain sensor, a stretchable metal/polymer composite film embedded with silver nanowires (AgNWs) was examined as a potential candidate. The combination of Ag film and AgNWs enabled the fabrication of a conductive film that was applied as a high sensitivity strain sensor, with gauge factors of 7.1 under the applied strain of 0–10% and 21.1 under the applied strain of 10–30%. Furthermore, the strain sensor was demonstrated to be highly reversible and remained stable after 1000 bending cycles. These results indicated that the AgNWs could act as elastic conductive bridges across cracks in the metal film to maintain high conductivity under tensile and bending loads. As such, the strain sensor engineered herein was successfully applied in the real-time detection and monitoring of large motions of joints and subtle motions of the mouth.

Superhydrophobic gradient wrinkle strain sensor with ultra-high sensitivity and broad strain range for motion monitoring

2021 ◽  
Vol 9 (15) ◽  
pp. 9634-9643
Author(s):  
Zhenming Chu ◽  
Weicheng Jiao ◽  
Yifan Huang ◽  
Yongting Zheng ◽  
Rongguo Wang ◽  
...  
Keyword(s):  
Human Body ◽  
Full Range ◽  
Strain Sensor ◽  
Strain Range ◽  
High Sensitivity

A graphene-based gradient wrinkle strain sensor with a broad range and ultra-high sensitivity was fabricated by a simple pre-stretching method. It can be applied to the detection of full-range human body motions.

scholarly journals Design of a Sensitive Balloon Sensor for Safe Human–Robot Interaction

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2163
Author(s):  
Dongjin Kim ◽  
Seungyong Han ◽  
Taewi Kim ◽  
Changhwan Kim ◽  
Doohoe Lee ◽  
...  
Keyword(s):  
High Performance ◽  
Strain Sensor ◽  
High Sensitivity ◽  
Human Robot Interaction ◽  
Large Area ◽  
Tactile Sensors ◽  
Robot Interaction ◽  
Mechanical Crack ◽  
Flexible Strain Sensor ◽  
Contact Sensing

As the safety of a human body is the main priority while interacting with robots, the field of tactile sensors has expanded for acquiring tactile information and ensuring safe human–robot interaction (HRI). Existing lightweight and thin tactile sensors exhibit high performance in detecting their surroundings. However, unexpected collisions caused by malfunctions or sudden external collisions can still cause injuries to rigid robots with thin tactile sensors. In this study, we present a sensitive balloon sensor for contact sensing and alleviating physical collisions over a large area of rigid robots. The balloon sensor is a pressure sensor composed of an inflatable body of low-density polyethylene (LDPE), and a highly sensitive and flexible strain sensor laminated onto it. The mechanical crack-based strain sensor with high sensitivity enables the detection of extremely small changes in the strain of the balloon. Adjusting the geometric parameters of the balloon allows for a large and easily customizable sensing area. The weight of the balloon sensor was approximately 2 g. The sensor is employed with a servo motor and detects a finger or a sheet of rolled paper gently touching it, without being damaged.

scholarly journals Tin Disulfide-Coated Microfiber for Humidity Sensing with Fast Response and High Sensitivity

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 648
Author(s):  
Aijie Liang ◽  
Jingyuan Ming ◽  
Wenguo Zhu ◽  
Heyuan Guan ◽  
Xinyang Han ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
Small Diameter ◽  
High Sensitivity ◽  
Large Change ◽  
Small Variation ◽  
Response Speed ◽  
Fast Response ◽  
Tin Disulfide ◽  
Recovery Times ◽  
Response And Recovery

Breath monitoring is significant in assessing human body conditions, such as cardiac and pulmonary symptoms. Optical fiber-based sensors have attracted much attention since they are immune to electromagnetic radiation, thus are safe for patients. Here, a microfiber (MF) humidity sensor is fabricated by coating tin disulfide (SnS2) nanosheets onto the surface of MF. The small diameter (~8 μm) and the long length (~5 mm) of the MF promise strong interaction between guiding light and SnS2. Thus, a small variation in the relative humidity (RH) will lead to a large change in optical transmitted power. A high RH sensitivity of 0.57 dB/%RH is therefore achieved. The response and recovery times are estimated to be 0.08 and 0.28 s, respectively. The high sensitivity and fast response speed enable our SnS2-MF sensor to monitor human breath in real time.

scholarly journals A Full-Range Flexible and Printed Humidity Sensor Based on a Solution-Processed P(VDF-TrFE)/Graphene-Flower Composite

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1915
Author(s):  
Shenawar Ali Khan ◽  
Muhammad Saqib ◽  
Muhammad Muqeet Rehman ◽  
Hafiz Mohammad Mutee Ur Rehman ◽  
Sheik Abdur Rahman ◽  
...  
Keyword(s):  
Active Layer ◽  
Humidity Sensor ◽  
High Reliability ◽  
Full Range ◽  
High Sensitivity ◽  
Fast Response ◽  
Considerable Change ◽  
Relative Humidity Range ◽  
Response And Recovery ◽  
Proportional Relationship

A novel composite based on a polymer (P(VDF-TrFE)) and a two-dimensional material (graphene flower) was proposed as the active layer of an interdigitated electrode (IDEs) based humidity sensor. Silver (Ag) IDEs were screen printed on a flexible polyethylene terephthalate (PET) substrate followed by spin coating the active layer of P(VDF-TrFE)/graphene flower on its surface. It was observed that this sensor responds to a wide relative humidity range (RH%) of 8–98% with a fast response and recovery time of 0.8 s and 2.5 s for the capacitance, respectively. The fabricated sensor displayed an inversely proportional response between capacitance and RH%, while a directly proportional relationship was observed between its impedance and RH%. P(VDF-TrFE)/graphene flower-based flexible humidity sensor exhibited high sensitivity with an average change of capacitance as 0.0558 pF/RH%. Stability of obtained results was monitored for two weeks without any considerable change in the original values, signifying its high reliability. Various chemical, morphological, and electrical characterizations were performed to comprehensively study the humidity-sensing behavior of this advanced composite. The fabricated sensor was successfully used for the applications of health monitoring and measuring the water content in the environment.

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