Hydrogel machines

Materials Today, Journal Year: 2020, Volume and Issue: 36, P. 102 - 124

Published: Jan. 28, 2020

Language: Английский

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Stretchable and tough conductive hydrogels for flexible pressure and strain sensors

Journal of Materials Chemistry B, Journal Year: 2020, Volume and Issue: 8(16), P. 3437 - 3459

Published: Jan. 1, 2020

Flexible pressure and strain sensors have great potential for applications in wearable implantable devices, soft robotics artificial skin. Compared to flexible based on filler/elastomer composites, conductive hydrogels are advantageous due their biomimetic structures properties, as well biocompatibility. Numerous chemical structural designs provide unlimited opportunities tune the properties performance of match various demands practical applications. Many electronically ionically been developed fabricate with different configurations, including resistance type capacitance type. The sensitivity, reliability stability hydrogel dependent network mechanical properties. This review focuses tough sensors. Representative strategies prepare stretchable, strong, self-healing briefly reviewed since these illuminating development hydrogels. Then, a general account is presented discussed. Recent advances designed sensory discussed detail. A series application devices reviewed. Some perspectives at end.

Language: Английский

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Liquid Metal Composites

Matter, Journal Year: 2020, Volume and Issue: 2(6), P. 1446 - 1480

Published: June 1, 2020

Language: Английский

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Recent advances in conductive hydrogels: classifications, properties, and applications

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 52(2), P. 473 - 509

Published: Dec. 9, 2022

Hydrogel-based conductive materials for smart wearable devices have attracted increasing attention due to their excellent flexibility, versatility, and outstanding biocompatibility. This review presents the recent advances in multifunctional hydrogels electronic devices. First, with different components are discussed, including pure single network based on polymers, additional additives (i.e., nanoparticles, nanowires, nanosheets), double additives. Second, a variety of functionalities, self-healing, super toughness, self-growing, adhesive, anti-swelling, antibacterial, structural color, hydrophobic, anti-freezing, shape memory external stimulus responsiveness introduced detail. Third, applications flexible illustrated strain sensors, supercapacitors, touch panels, triboelectric nanogenerator, bioelectronic devices, robot). Next, current challenges facing summarized. Finally, an imaginative but reasonable outlook is given, which aims drive further development future.

Language: Английский

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Development of Conductive Hydrogels for Fabricating Flexible Strain Sensors

Small, Journal Year: 2021, Volume and Issue: 18(5)

Published: Oct. 17, 2021

Abstract Conductive hydrogels can be prepared by incorporating various conductive materials into polymeric network hydrogels. In recent years, have been developed and applied in the field of strain sensors owing to their unique properties, such as electrical conductivity, mechanical self‐healing, anti‐freezing properties. These remarkable properties allow hydrogel‐based show excellent performance for identifying external stimuli detecting human body movement, even at subzero temperatures. This review summarizes application fabrication working different modes. Finally, a brief prospectus development future is provided.

Language: Английский

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Carbon Nanotubes/Hydrophobically Associated Hydrogels as Ultrastretchable, Highly Sensitive, Stable Strain, and Pressure Sensors

ACS Applied Materials & Interfaces, Journal Year: 2020, Volume and Issue: 12(4), P. 4944 - 4953

Published: Jan. 8, 2020

Conductive hydrogels have become one of the most promising materials for skin-like sensors because their excellent biocompatibility and mechanical flexibility. However, limited stretchability, low toughness, fatigue resistance lead to a narrow sensing region insufficient durability hydrogel-based sensors. In this work, an extremely stretchable, highly tough, anti-fatigue conductive nanocomposite hydrogel is prepared by integrating hydrophobic carbon nanotubes (CNTs) into hydrophobically associated polyacrylamide (HAPAAm) hydrogel. hydrogel, amphiphilic sodium dodecyl sulfate was used ensure uniform dispersion CNTs in network, interactions between matrix CNT surface formed, greatly improving properties The obtained CNTs/HAPAAm showed stretchability (ca. 3000%), toughness (3.42 MJ m-3), great property. Moreover, it exhibits both high tensile strain sensitivity wide ranges (gauge factor = 4.32, up 1000%) linear (0.127 kPa-1) large-pressure within 0-50 kPa. can sensitively stably detect full-range human activities (e.g., elbow rotation, finger bending, swallowing motion, pronouncing) handwriting, demonstrating hydrogel's potential as wearable pressure flexible devices.

Language: Английский

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Multifunctional conductive hydrogels and their applications as smart wearable devices

Journal of Materials Chemistry B, Journal Year: 2021, Volume and Issue: 9(11), P. 2561 - 2583

Published: Jan. 1, 2021

Recently, hydrogel-based conductive materials and their applications as smart wearable devices have been paid tremendous attention due to high stretchability, flexibility, excellent biocompatibility. Compared with single functional hydrogels, multifunctional hydrogels are more advantageous match various demands for practical applications. This review focuses on applied devices. Representative strategies conduction of discussed firstly: (1) electronic based the fillers (2) ionic charged ions. Then, common intensive research multiple functionalities such mechanical properties, sensory anti-freezing moisturizing adhesion self-healing properties is presented. The in human motion sensors, skins, personal healthcare diagnosis provided third part. Finally, we offer our perspective open challenges future areas interest used

Language: Английский

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Ultra‐Sensitive, Deformable, and Transparent Triboelectric Tactile Sensor Based on Micro‐Pyramid Patterned Ionic Hydrogel for Interactive Human–Machine Interfaces

Advanced Science, Journal Year: 2022, Volume and Issue: 9(10)

Published: Jan. 31, 2022

Abstract Rapid advances in wearable electronics and mechno‐sensational human–machine interfaces impose great challenges developing flexible deformable tactile sensors with high efficiency, ultra‐sensitivity, environment‐tolerance, self‐sustainability. Herein, a hydrogel sensor (THS) based on micro‐pyramid‐patterned double‐network (DN) ionic organohydrogels to detect subtle pressure changes by measuring the variations of triboelectric output signal without an external power supply is reported. By first time pyramidal‐patterned fabrication method laminated polydimethylsiloxane (PDMS) encapsulation process, self‐powered THS shows advantages remarkable flexibility, good transparency (≈85%), excellent sensing performance, including extraordinary sensitivity (45.97 mV Pa −1 ), fast response (≈20 ms), very low limit detection (50 Pa) as well stability (36 000 cycles). Moreover, LiBr immersion treatment method, possesses long‐term hyper anti‐freezing anti‐dehydrating properties, broad environmental tolerance (−20 60 °C), instantaneous peak density 20 µW cm −2 , providing reliable contact outputs different materials detecting slight human motions. integrating acquisition/process circuit, self‐power ability utilized switching button control electric appliances robotic hands simulating finger gestures, offering its potentials for multi‐functional electronic applications.

Language: Английский

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Polyvinyl Alcohol-Stabilized Liquid Metal Hydrogel for Wearable Transient Epidermal Sensors

ACS Applied Materials & Interfaces, Journal Year: 2019, Volume and Issue: 11(50), P. 47358 - 47364

Published: Nov. 22, 2019

Wearable epidermal sensors are attracting growing interests in human activity monitoring and flexible touch display, but they still limited by the poor self-healing property difficult dissolvable feature. Herein, we report polyvinyl alcohol (PVA)-stabilized liquid metal particles (LMPs) (PVA-LMPs) hydrogels with excellent performance feature for wearable sensors, constructed dispersing LMPs of eutectic gallium indium into borate-modified PVA polymer networks. Interestingly, PVA-LMPs exhibited electrically mechanically ability. Moreover, hydrogel can be fabricated as which accurately monitor activities. Additionally, dissolvable, showing an attractive on demand transient electronics. It is demonstrated that hydroxyl groups stabilize via hydrogen-bonding interactions. Furthermore, dynamic cross-linking bonds between rupture coalesce reversibly network, endow both This work shows potential constructing next-generation multifunctional hydrogel-based monitoring, healthcare diagnosis, portable electronics, robot tactile systems.

Language: Английский

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Self-Recovery, Fatigue-Resistant, and Multifunctional Sensor Assembled by a Nanocellulose/Carbon Nanotube Nanocomplex-Mediated Hydrogel

ACS Applied Materials & Interfaces, Journal Year: 2021, Volume and Issue: 13(42), P. 50281 - 50297

Published: Oct. 12, 2021

Flexible sensors have attracted great research interest due to their applications in artificial intelligence, wearable electronics, and personal health management. However, the inherent brittleness of common hydrogels, preparing a hydrogel-based sensor integrated with excellent flexibility, self-recovery, antifatigue properties still remains challenge date. In this study, type physically chemically dual-cross-linked conductive hydrogels based on 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofiber (TOCN)-carrying carbon nanotubes (CNTs) polyacrylamide (PAAM) matrix via facial one-pot free-radical polymerization is developed for multifunctional sensing application. Inside hierarchical gel network, TOCNs not only serve as nanoreinforcement toughening effect but also efficiently assist homogeneous distribution CNTs hydrogel matrix. The optimized TOCN-CNT/PAAM integrates high compressive (∼2.55 MPa at 60% strain) tensile (∼0.15 MPa) strength, intrinsic self-recovery property (recovery efficiency >92%), capacity under both cyclic stretching pressing. assembled by exhibit strain sensitivity (gauge factor ≈11.8 100-200% good pressure ability over large range (0-140 kPa), which can effectively detect subtle large-scale human motions through repeatable stable electrical signals even after 100 loading-unloading cycles. comprehensive performance superior those most gel-based previously reported, indicating its potential devices healthcare systems motion monitoring.

Language: Английский

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