scholarly journals Room-Temperature Self-Healing Elastomer based on Van der Waals Forces in Air and under Water

2021 ◽  
Vol 2083 (2) ◽  
pp. 022066
Author(s):  
Pengying Niu ◽  
Beibei Liu ◽  
Huanjun Li
Keyword(s):  
Room Temperature ◽  
Van Der Waals ◽  
Strong Acid ◽  
Van Der Waals Forces ◽  
The Self ◽  
Self Healing ◽  
Wearable Electronic ◽  
Self Repair ◽  
High Humidity Environment ◽  
Wearable Electronic Devices

Abstract With the development of flexible wearable electronic devices, researches on self-healing conductive materials have become prevalent. However, the self-healing performance of most conductive self-healing materials is commonly achieved by the external stimulus that may cause damage to the equipment. Pparticularly, these self-healing materials may lose the self-healing properties when exposed to a high-humidity environment. Here, we adopted two hydrophobic monomers (2-methoxyethyl acrylate and ethyl methacrylate) to obtain a self-healing elastomer that could display self-healing properties in air or under water though van der Waals forces. The quality and mechanical properties of the elastomer material could keep stable after stored under water for half a month. This elastomer material was capable of self-healing in different environments with self-repair efficiencies more than 50% in deionized water, strong acid solution and strong alkaline solution. The self-repair efficiencies were up to 77% at room temperature(T=25°C) and 64% at low temperature (T=-20°C) in air.

scholarly journals Foldable and washable textile-based OLEDs with a multi-functional near-room-temperature encapsulation layer for smart e-textiles

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
So Yeong Jeong ◽  
Hye Rin Shim ◽  
Yunha Na ◽  
Ki Suk Kang ◽  
Yongmin Jeon ◽  
...  
Keyword(s):  
Room Temperature ◽  
Wearable Electronics ◽  
Ambient Conditions ◽  
Light Emitting ◽  
Stable Operating ◽  
Mechanical Durability ◽  
Potential Applications ◽  
Wearable Electronic ◽  
Data Signal ◽  
Wearable Electronic Devices

AbstractWearable electronic devices are being developed because of their wide potential applications and user convenience. Among them, wearable organic light emitting diodes (OLEDs) play an important role in visualizing the data signal processed in wearable electronics to humans. In this study, textile-based OLEDs were fabricated and their practical utility was demonstrated. The textile-based OLEDs exhibited a stable operating lifetime under ambient conditions, enough mechanical durability to endure the deformation by the movement of humans, and washability for maintaining its optoelectronic properties even in water condition such as rain, sweat, or washing. In this study, the main technology used to realize this textile-based OLED was multi-functional near-room-temperature encapsulation. The outstanding impermeability of TiO2 film deposited at near-room-temperature was demonstrated. The internal residual stress in the encapsulation layer was controlled, and the device was capped by highly cross-linked hydrophobic polymer film, providing a highly impermeable, mechanically flexible, and waterproof encapsulation.

scholarly journals Effect of Microwave Processing and Glass Inclusions on Thermoelectric Properties of P-Type Bismuth Antimony Telluride Alloys for Wearable Applications

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4524
Author(s):  
Amin Nozariasbmarz ◽  
Daryoosh Vashaee
Keyword(s):  
Seebeck Coefficient ◽  
Thermoelectric Materials ◽  
Room Temperature ◽  
Electronic Devices ◽  
Microwave Processing ◽  
Glass Inclusion ◽  
Wearable Electronic ◽  
P Type ◽  
Wearable Electronic Devices ◽  
Body Heat

Depending on the application of bismuth telluride thermoelectric materials in cooling, waste heat recovery, or wearable electronics, their material properties, and geometrical dimensions should be designed to optimize their performance. Recently, thermoelectric materials have gained a lot of interest in wearable electronic devices for body heat harvesting and cooling purposes. For efficient wearable electronic devices, thermoelectric materials with optimum properties, i.e., low thermal conductivity, high Seebeck coefficient, and high thermoelectric figure-of-merit (zT) at room temperature, are demanded. In this paper, we investigate the effect of glass inclusion, microwave processing, and annealing on the synthesis of high-performance p-type (BixSb1−x)2Te3 nanocomposites, optimized specially for body heat harvesting and body cooling applications. Our results show that glass inclusion could enhance the room temperature Seebeck coefficient by more than 10% while maintaining zT the same. Moreover, the combination of microwave radiation and post-annealing enables a 25% enhancement of zT at room temperature. A thermoelectric generator wristband, made of the developed materials, generates 300 μW power and 323 mV voltage when connected to the human body. Consequently, MW processing provides a new and effective way of synthesizing p-type (BixSb1−x)2Te3 alloys with optimum transport properties.

scholarly journals 3D Printing of a Self-Healing Thermoplastic Polyurethane through FDM: From Polymer Slab to Mechanical Assessment

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 305
Author(s):  
Linda Ritzen ◽  
Vincenzo Montano ◽  
Santiago J. Garcia
Keyword(s):  
3D Printing ◽  
Room Temperature ◽  
Thermoplastic Polyurethane ◽  
The Self ◽  
Added Value ◽  
Fused Deposition Modelling ◽  
Full Potential ◽  
Self Healing ◽  
Fused Deposition ◽  
3D Printed

The use of self-healing (SH) polymers to make 3D-printed polymeric parts offers the potential to increase the quality of 3D-printed parts and to increase their durability and damage tolerance due to their (on-demand) dynamic nature. Nevertheless, 3D-printing of such dynamic polymers is not a straightforward process due to their polymer architecture and rheological complexity and the limited quantities produced at lab-scale. This limits the exploration of the full potential of self-healing polymers. In this paper, we present the complete process for fused deposition modelling of a room temperature self-healing polyurethane. Starting from the synthesis and polymer slab manufacturing, we processed the polymer into a continuous filament and 3D printed parts. For the characterization of the 3D printed parts, we used a compression cut test, which proved useful when limited amount of material is available. The test was able to quasi-quantitatively assess both bulk and 3D printed samples and their self-healing behavior. The mechanical and healing behavior of the 3D printed self-healing polyurethane was highly similar to that of the bulk SH polymer. This indicates that the self-healing property of the polymer was retained even after multiple processing steps and printing. Compared to a commercial 3D-printing thermoplastic polyurethane, the self-healing polymer displayed a smaller mechanical dependency on the printing conditions with the added value of healing cuts at room temperature.

Application of super-stretched self-healing elastomer based on methyl vinyl silicone rubber for wearable electronic sensors

2021 ◽  
Author(s):  
Tianwen Yu ◽  
Yifei Shan ◽  
Zhixi Li ◽  
Xiaoxiao Wang ◽  
Hua‘nan Cui ◽  
...  
Keyword(s):  
Silicone Rubber ◽  
Wearable Sensors ◽  
Electronic Devices ◽  
Self Healing ◽  
Relevant Research ◽  
Methyl Vinyl ◽  
Wearable Electronic ◽  
Low Sensitivity ◽  
Wearable Electronic Devices ◽  
Electronic Sensors

Wearable electronic devices, represented by wearable sensors with self-healing performance, are key to the development of the relevant research. However, problems of sensors as low sensitivity, flexibility, durability and self-healing...

Key-and-lock commodity self-healing copolymers

Science ◽  
2018 ◽  
Vol 362 (6411) ◽  
pp. 220-225 ◽  
Author(s):  
Marek W. Urban ◽  
Dmitriy Davydovich ◽  
Ying Yang ◽  
Tugba Demir ◽  
Yunzhi Zhang ◽  
...  
Keyword(s):  
Butyl Acrylate ◽  
Van Der Waals ◽  
Mechanical Damage ◽  
Random Copolymer ◽  
Van Der Waals Forces ◽  
Random Component ◽  
Self Healing ◽  
Ambient Conditions ◽  
Chemical Damage ◽  
External Intervention

Self-healing materials are notable for their ability to recover from physical or chemical damage. We report that commodity copolymers, such as poly(methyl methacrylate)/n-butyl acrylate [p(MMA/nBA)] and their derivatives, can self-heal upon mechanical damage. This behavior occurs in a narrow compositional range for copolymer topologies that are preferentially alternating with a random component (alternating/random) and is attributed to favorable interchain van der Waals forces forming key-and-lock interchain junctions. The use of van der Waals forces instead of supramolecular or covalent rebonding or encapsulated reactants eliminates chemical and physical alterations and enables multiple recovery upon mechanical damage without external intervention. Unlike other self-healing approaches, perturbation of ubiquitous van der Waals forces upon mechanical damage is energetically unfavorable for interdigitated alternating/random copolymer motifs that facilitate self-healing under ambient conditions.

scholarly journals Dynamic Covalent Bonds of Si-OR and Si-OSi Enabled A Stiff Polymer to Heal and Recycle at Room Temperature

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2680
Author(s):  
Ping Fan ◽  
Can Xue ◽  
Xiantai Zhou ◽  
Zujin Yang ◽  
Hongbing Ji
Keyword(s):  
Mechanical Properties ◽  
Small Molecule ◽  
Potential Application ◽  
Room Temperature ◽  
The Self ◽  
Self Healing ◽  
Bending Properties ◽  
Covalent Bonds ◽  
Model Experiments ◽  
Molecule Model

As stiff polymers are difficult to self-heal, the balance between polymers’ self-healing ability and mechanical properties is always a big challenge. Herein, we have developed a novel healable stiff polymer based on the Si-OR and Si-OSi dynamic covalent bonds. The self-healing mechanism was tested and proved by the small molecule model experiments and the contrast experiments of polymers. This polymer possesses excellent tensile, bending properties as well as room temperature self-healing abilities. Moreover, due to the sticky and shapeable properties under wetting conditions, the polymer could be used as an adhesive. Besides, even after four cycles of recycling, the polymer maintains its original properties, which meets the requirements of recyclable materials. It was demonstrated that the polymer exhibits potential application in some fields, such as recyclable materials and healable adhesives.

A Self-Repair Mode for Capillary Reinforced Polymer Composite

2013 ◽  
Vol 575-576 ◽  
pp. 147-150
Author(s):  
Xin Hua Yuan ◽  
Ji Ye Wu ◽  
Yong Qiang Liu ◽  
Jun Xia Mao ◽  
Xue Tao Ou ◽  
...  
Keyword(s):  
Impact Damage ◽  
The Self ◽  
Self Healing ◽  
Reinforced Polymer ◽  
Flexural Testing ◽  
Reinforced Plastic ◽  
Crack Morphology ◽  
Healing Agent ◽  
Self Repair ◽  
The Impact

The paper describes a novel capillary reinforced plastic which can self-repair the impact damage in polymer composites through employing a bio-mimetic approach. A epoxy resin E-51 and harder WSR706# was used as the healing agent, the two components being filled in to different directions (0°and 90° fibers). Impact test and tensile test were used as a measure of the self-healing effectiveness. The results of flexural testing have shown that strength lost after impact damage can be restored by the self-healing effect with healing agent stored in capillaries, and a significant fraction (about 79%) of lost mechanical strength is restored by this effect. At the same time, the paper also studied the morphology of fracture surface of no embedded and capillaries embedded sample. And micrographs of crack morphology which has been healed have been observed.

Wafer-Bonding and Thinning Technologies

MRS Bulletin ◽  
1998 ◽  
Vol 23 (12) ◽  
pp. 30-34 ◽  
Author(s):  
Cynthia A. Desmond-Colinge ◽  
Ulrich Gösele
Keyword(s):  
Gallium Arsenide ◽  
Wafer Bonding ◽  
Room Temperature ◽  
Van Der Waals ◽  
Van Der Waals Forces ◽  
Crystalline Material ◽  
Single Crystalline ◽  
Fusion Bonding

“Wafer bonding” refers to the phenomenon in which mirror-polished, flat, and clean wafers of almost any material—when brought into contact at room temperature—are locally attracted to each other by van der Waals forces and adhere or “bond” to each other. Wafer bonding is alternatively also known as “direct bonding” or “fusion bonding,” or more colloquially as “gluing without glue.” Although this is by no means required, in most cases, the wafers involved in actual applications are typical semiconductor wafers consisting of single-crystalline material used in microelectronics or optoelectronics such as silicon or gallium arsenide.

Enhancing Energy Harvesting Performance of PDMS based Piezocomposites via Synergistic Effect

2021 ◽  
Author(s):  
Yijin Hao ◽  
Yudong Hou ◽  
Hui Xu ◽  
Xin Gao ◽  
Mupeng Zheng ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Electronic Devices ◽  
Electrical Energy ◽  
The Self ◽  
Energy Requirements ◽  
Vibration Energy ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Wearable Electronic ◽  
Wearable Electronic Devices

Due to the self-supplied energy requirements of wearable electronic devices, flexible piezoelectric energy harvesters (FPEHs) that can convert waste vibration energy in the environment into electrical energy have received widespread...

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