High Toughness Multifunctional Organic Hydrogels for Flexible Strain and Temperature Sensor

Abstract Highly stretched and conductive hydrogels, especially synthetized from natural polymers, are beneficial for highly stretched electronic equipment which is applied in extreme environment. We designed and prepared robust and tough alginate hydrogels (GMA-SA-PAM) using the ingenious strategy of fully interpenetrating cross-linking, in which the glycidyl methacrylate (GMA) was used to modify sodium alginate (SA) and then copolymerized with acrylamide (AM) and methylenebisacrylamide (BIS) as cross-linkers. The complete cross-linked structures can averagely dissipate energy and the polymer structures can maintain hydrogels that are three-dimensional to greatly improve the mechanical performance of hydrogels. The GMA-SA-PAM hydrogels display ultra-stretchable (strain up to ∼407% of tensile strain) and highly compressible (∼57% of compression strain) properties. In addition, soaking the GMA-SA-PAM hydrogel in 5 wt% NaCl solution also endows the conductivity of the hydrogel (this hydrogel was named as GSP-Na) with excellent conductive properties (5.26 S m−1). The GSP-Na hydrogel with high stability, durability, as well as wide range extent sensor is also demonstrated by researching the electrochemical signals and showing the potential for applications in wearable and quickly responded electronics.

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Stimuli-responsive conductive hydrogels: design, property and applications

Materials Chemistry Frontiers ◽

10.1039/d0qm00868k ◽

2021 ◽

Author(s):

Zexing Deng ◽

Rui Yu ◽

Baolin Guo

Keyword(s):

Conductive Polymers ◽

Research Field ◽

Stimuli Responsive ◽

Conductive Hydrogel ◽

Design Property ◽

Conductive Hydrogels

Stimuli-responsive conductive hydrogel has been emerged as a new surging concept in hydrogel research field due to its combined advantages of stimuli-responsivity and conductivity from conductive polymers (such as polyaniline,...

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Robust Conductive Hydrogels with Ultrafast Self-Recovery and Nearly Zero Response Hysteresis for Epidermal Sensors

Nanomaterials ◽

10.3390/nano11071854 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1854

Author(s):

Xiuru Xu ◽

Chubin He ◽

Feng Luo ◽

Hao Wang ◽

Zhengchun Peng

Keyword(s):

Guar Gum ◽

Strain Range ◽

Sio2 Nanoparticles ◽

Fast Response ◽

Gauge Factor ◽

Practical Applications ◽

Hydroxypropyl Guar ◽

Stable Chemical ◽

Conductive Hydrogel ◽

Conductive Hydrogels

Robust conductive hydrogels are in great demand for the practical applications of smart soft robots, epidermal electronics, and human–machine interactions. We successfully prepared nanoparticles enhanced polyacrylamide/hydroxypropyl guar gum/acryloyl-grafted chitosan quaternary ammonium salt/calcium ions/SiO2 nanoparticles (PHC/Ca2+/SiO2 NPs) conductive hydrogels. Owing to the stable chemical and physical hybrid crosslinking networks and reversible non-covalent interactions, the PHC/Ca2+/SiO2 NPs conductive hydrogel showed good conductivity (~3.39 S/m), excellent toughness (6.71 MJ/m3), high stretchability (2256%), fast self-recovery (80% within 10 s, and 100% within 30 s), and good fatigue resistance. The maximum gauge factor as high as 66.99 was obtained, with a wide detectable strain range (from 0.25% to 500% strain), the fast response (25.00 ms) and recovery time (86.12 ms), excellent negligible response hysteresis, and good response stability. The applications of monitoring the human’s body movements were demonstrated, such as wrist bending and pulse tracking.

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Preparation of Carbon Fiber-Polyacrylamide Composite Hydrogel Based on Surface Electric-Initiated Polymerization

Journal of Nanoelectronics and Optoelectronics ◽

10.1166/jno.2021.3028 ◽

2021 ◽

Vol 16 (6) ◽

pp. 861-868

Author(s):

Mengge Lv ◽

Xinfang Wei ◽

Liwen Peng

Keyword(s):

Composite Material ◽

Carbon Fiber ◽

Electrochemical Polymerization ◽

Crosslinking Agent ◽

Monomer Concentration ◽

Conductive Filler ◽

Composite Effect ◽

Conductive Hydrogel ◽

Graft Modification ◽

Conductive Hydrogels

Conductive hydrogels have shown excellent application prospects in the fields of bioelectronics, tissue engineering, wearable devices, etc. However, its poor compatibility at the organic-inorganic interface affects its mechanical strength and limits its wide application. We prepared carbon fiber-polyacrylamide organic-inorganic composite material by electrochemical polymerization using N,N-methylenebisacrylamide as the crosslinking agent, acrylamide as the monomer, and carbon fiber as the conductive filler. It forms a conductive hydrogel after absorbing water. The effects of monomer concentration, reaction time, and current on the composite material were investigated in this article. The experimental results show that a large number of irregular bumps are produced on the surface of carbon fiber, and various characterization tests show that it is polyacrylamide (PAM) that successfully attached to carbon fiber. Under the same electrochemical polymerization time, the current density and monomer concentration have little effect on the molecular weight which mainly concentrated around 6.2 × 105. The graft modification of PAM reduces the defects on the surface of the carbon fiber, and the composite effect is good.

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Bioinspired tough, conductive hydrogels with thermally reversible adhesiveness based on nanoclay confined NIPAM polymerization and a dopamine modified polypeptide

Materials Chemistry Frontiers ◽

10.1039/c9qm00582j ◽

2020 ◽

Vol 4 (1) ◽

pp. 189-196 ◽

Cited By ~ 3

Author(s):

Xiang Di ◽

Chen Hang ◽

Yue Xu ◽

Qiyue Ma ◽

Feifan Li ◽

...

Keyword(s):

Conductive Hydrogel ◽

Conductive Hydrogels

A multifunctional conductive hydrogel with controllable adhesiveness, high strechability and excellent biocompatibility based on PDAEA, clay, and PNIPAM.

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Incorporation of Conductive Materials into Hydrogels for Tissue Engineering Applications

Polymers ◽

10.3390/polym10101078 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1078 ◽

Cited By ~ 30

Author(s):

Ji Min ◽

Madhumita Patel ◽

Won-Gun Koh

Keyword(s):

Tissue Engineering ◽

Electrical Properties ◽

Cardiac Tissue ◽

In Situ Polymerization ◽

Nerve Tissue ◽

Conductive Materials ◽

Conductive Hydrogel ◽

Conductive Hydrogels ◽

Electrical Properties Of Tissues

In the field of tissue engineering, conductive hydrogels have been the most effective biomaterials to mimic the biological and electrical properties of tissues in the human body. The main advantages of conductive hydrogels include not only their physical properties but also their adequate electrical properties, which provide electrical signals to cells efficiently. However, when introducing a conductive material into a non-conductive hydrogel, a conflicting relationship between the electrical and mechanical properties may develop. This review examines the strengths and weaknesses of the generation of conductive hydrogels using various conductive materials such as metal nanoparticles, carbons, and conductive polymers. The fabrication method of blending, coating, and in situ polymerization is also added. Furthermore, the applications of conductive hydrogel in cardiac tissue engineering, nerve tissue engineering, and bone tissue engineering and skin regeneration are discussed in detail.

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Highly stretchable, self-adhesive, biocompatible, conductive hydrogels as fully polymeric strain sensors

Journal of Materials Chemistry A ◽

10.1039/d0ta07390c ◽

2020 ◽

Vol 8 (39) ◽

pp. 20474-20485

Author(s):

Dong Zhang ◽

Yijing Tang ◽

Yanxian Zhang ◽

Fengyu Yang ◽

Yonglan Liu ◽

...

Keyword(s):

Strain Sensors ◽

Surface Adhesion ◽

Human Movements ◽

Conductive Hydrogel ◽

Highly Stretchable ◽

Strong Surface ◽

Conductive Hydrogels

A new fully polymeric conductive hydrogel sensor with IPN structure was developed, which achieved ultra-high stretchability, strong surface adhesion, and high sensing stability in response to both large and subtle human movements.

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Dense Hydrogen-Bonding Network Boosts Ionic Conductive Hydrogels with Extremely High Toughness, Rapid Self-Recovery, and Autonomous Adhesion for Human-Motion Detection

Research ◽

10.34133/2021/9761625 ◽

2021 ◽

Vol 2021 ◽

pp. 1-14

Author(s):

Bing Zhang ◽

Xu Zhang ◽

Kening Wan ◽

Jixin Zhu ◽

Jingsan Xu ◽

...

Keyword(s):

Hydrogen Bonding ◽

Dissipative Particle Dynamics ◽

Mean Square Displacement ◽

Human Motion ◽

Imidazolium Chloride ◽

High Toughness ◽

Human Motion Detection ◽

Highly Stretchable ◽

Hydrogen Bonding Network ◽

Conductive Hydrogels

The construction of ionic conductive hydrogels with high transparency, excellent mechanical robustness, high toughness, and rapid self-recovery is highly desired yet challenging. Herein, a hydrogen-bonding network densification strategy is presented for preparing a highly stretchable and transparent poly(ionic liquid) hydrogel (PAM-r-MVIC) from the perspective of random copolymerization of 1-methyl-3-(4-vinylbenzyl) imidazolium chloride and acrylamide in water. Ascribing to the formation of a dense hydrogen-bonding network, the resultant PAM-r-MVIC exhibited an intrinsically high stretchability (>1000%) and compressibility (90%), fast self-recovery with high toughness (2950 kJ m-3), and excellent fatigue resistance with no deviation for 100 cycles. Dissipative particle dynamics simulations revealed that the orientation of hydrogen bonds along the stretching direction boosted mechanical strength and toughness, which were further proved by the restriction of molecular chain movements ascribing to the formation of a dense hydrogen-bonding network from mean square displacement calculations. Combining with high ionic conductivity over a wide temperature range and autonomous adhesion on various surfaces with tailored adhesive strength, the PAM-r-MVIC can readily work as a highly stretchable and healable ionic conductor for a capacitive/resistive bimodal sensor with self-adhesion, high sensitivity, excellent linearity, and great durability. This study might provide a new path of designing and fabricating ionic conductive hydrogels with high mechanical elasticity, high toughness, and excellent fatigue resilience for skin-inspired ionic sensors in detecting complex human motions.

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