The swift progression of high-density chiplet packaging, propelled by the artificial intelligence revolution, has precipitated a critical need for high-performance chip-scale thermal interface materials (TIMs). The elevated thermal resistance, limited interfacial adhesion, and mechanical flexibility intrinsic to silicone systems present a substantial challenge in meeting reliability standards amidst chip warpage. This particular matter underscores a significant performance bottleneck within existing high-end TIMs. In this study, we present poly(ionic liquid)s (PILs) as an innovative matrix for TIMs. Our findings highlight the unique properties of PILs, showcasing a low elastic modulus (60 kPa), exceptional flexibility and stretchability (>3800%), high adhesion to diverse substrates (up to 4.10 MPa), favorable filler compatibility, remarkable thermal stability, and prompt self-healing capabilities coupled with recyclability. The collective findings suggest that the PIL serves as an ideal matrix for heat transfer. As a proof of concept, PIL blended with liquid metal was straightforwardly combined to produce a TIM, exhibiting exceptional performance within practical encapsulated structures. The PIL-based TIM demonstrates substantial elongation at break (>350%), coupled with sustained high adhesion strength (up to 1.70 MPa), and exhibits favorable thermal conductivity in package testing. This study presents an innovative TIM matrix with the potential to enhance existing TIM systems, delivering significant performance benefits compared to silicones. Besides elucidating their multifaceted characteristics, this study forecasts an expanded range of applications for PILs, along with laying the groundwork for advancing next-generation TIMs.

Diabetic wounds are serious clinical complications which manifest wet condition due to the mass exudate, along with disturbed regulation of inflammation, severe oxidative stress and repetitive bacterial infection. Existing treatments for diabetic wounds remain unsatisfactory due to the lack of ideal dressings that encompass mechanical performance, adherence to moist tissue surfaces, quick repair, and diverse therapeutic benefits. Herein, we fabricated a wet adhesive, self-healing, glucose-responsive drug releasing hydrogel with efficient antimicrobial and pro-healing properties for diabetic wound treatment. PAE hydrogel was constructed with poly(acrylic acid-co-acrylamide) (AA-Am) integrated with a dynamic E-F crosslinker, which consisted of epigallocatechin gallate (EGCG) and 4-(2-acrylamidoethylcarbamoyl)-3-fluorophenylboronic acid (AFPBA). Due to the dynamic crosslinking nature of boronate esters, abundant catechol groups and hydrogen bonding, PAE hydrogel demonstrated excellent mechanical properties with about 1000 % elongation, robust adhesion to moist tissues, fast self-healing, and absorption of biofluids of 10 times of its own weight. Importantly, PAE hydrogel exhibited sustained and glucose-responsive release of EGCG. Together, the bioactive PAE hydrogel had effective antibacterial, antioxidative, and anti-inflammatory properties in vitro, and accelerated diabetic wound healing in rats via reducing tissue-inflammatory response, enhancing angiogenesis, and reprogramming of macrophages. Overall, this versatile hydrogel provides a straightforward solution for the treatment of diabetic wound, and shows potential for other wound-related application scenarios.

Self-healing covalent adaptable networks (CANs) are not only of fundamental interest but also of practical importance for achieving carbon neutrality and sustainable development. However, there is a trade-off between the mobility and cross-linking structure of CANs, making it challenging to develop CANs with excellent mechanical properties and high self-healing efficiency. Here, we report the utilization of a highly dynamic four-arm cross-linking unit with an internally catalyzed oxime-urethane group to obtain CAN-based ionogel with both high self-healing efficiency (>92.1%) at room temperature and superior mechanical properties (tensile strength 4.55 MPa and toughness 13.49 MJ m-3). This work demonstrates the significant potential of utilizing the synergistic electronic, spatial, and topological effects as a design strategy for developing high-performance materials.

Spinal cord injury (SCI) is a debilitating condition that can result in significant functional impairment and loss of quality of life. There is a growing interest in developing new therapies for SCI, and hydrogel-based multimodal therapeutic strategies have emerged as a promising approach. They offer several advantages for SCI repair, including biocompatibility, tunable mechanical properties, low immunogenicity, and the ability to deliver therapeutic agents. This article provides an overview of the recent advances in hydrogel-based therapy strategies for SCI repair, particularly within the past three years. We summarize the SCI hydrogels with varied characteristics such as phase-change hydrogels, self-healing hydrogel, oriented fibers hydrogel, and self-assembled microspheres hydrogel, as well as different functional hydrogels such as conductive hydrogels, stimuli-responsive hydrogels, adhesive hydrogel, antioxidant hydrogel, sustained-release hydrogel, etc. The composition, preparation, and therapeutic effect of these hydrogels are briefly discussed and comprehensively evaluated. In the end, the future development of hydrogels in SCI repair is prospected to inspire more researchers to invest in this promising field.

Research on self-healing materials spans multiple academic disciplines and employs a variety of methodologies. Nature has been a major source of inspiration for developing self-healing materials and will likely continue to inspire innovative ideas in this field. This review article covers the principles of self-healing mechanisms, focusing on both autonomous and non-autonomous procedures. It explores both intrinsic and extrinsic self-healing abilities by considering their components, structures, and design. Additionally, a detailed analysis of the application of these materials across various sectors is provided, including aerospace, automotive, marine, energy, medical and healthcare, military, and construction. Finally, the review paper highlights the advancements in encapsulation technologies for microcapsules, their thermal stability, their mechanical properties, and the compatibility of healing agents with the matrix, which play a crucial role in the effectiveness of self-healing processes.

The commonly used ultraviolet ray (UV) curing coatings have the characteristics of fast curing speed, high hardness, strong abrasion resistance, etc. However, the self-healing properties of UV coatings after being damaged still need to be improved. Self-healing microcapsules can alleviate this problem. The UV top coating itself has good properties, so it can be directly chosen as the core material of microcapsules. UV top coating microcapsules can be added to the UV top coating to increase the self-healing properties of the UV coating to achieve the purpose of better protection of the UV coating and fiberboards. UV top coating microcapsules were prepared and added in different contents to characterize the effect on the physical, chemical, and self-healing properties of the UV coating on a fiberboard surface. The 1#, 2#, and 3# UV top coating microcapsules that were prepared with emulsifier HLB values of 10.04, 10.88, and 11.72, respectively, were added to the UV top coating at contents of 2.0%, 4.0%, 6.0%, 8.0%, and 10.0%. The UV coatings were applied to the fiberboard using a method of two primers and two top coatings, in which no microcapsule was added in the primer, and were tested and analyzed. The results showed that when the content of microcapsules was greater than 6.0%, close to 8.0%, the excessive density of microcapsules produced stacking and extrusion between the microcapsules. As a result, the core material could not flow out smoothly when part of the microcapsule was ruptured. The outflow of the core material was not efficiently utilized, thus leading to a decrease in the self-healing rate. The 2# UV top coating microcapsules of 4.0% made the UV coatings reach the self-healing rate of 26.41%. The self-healing rate of the UV coatings prepared with the 3# UV top coating microcapsules with 6.0% was up to 26.58%. The UV coatings prepared with the 1# UV top coating microcapsules of 6.0% had the highest self-healing rate among the three groups, up to 27.32%. The UV coatings of this group had the best comprehensive properties with a chromatic aberration ΔE of 4.08, a gloss of 1.10 GU, a reflectance of 17.13%, an adhesion grade of 3, a hardness of 3H, a grade 3 of impact resistance, and a roughness of 1.677 μm. An investigation of the UV coatings on fiberboard surfaces with the content of UV top coating microcapsules can provide support for the optimization of the self-healing properties of UV coatings and can also provide innovative ideas for the preparation of the self-healing coatings on fiberboard surfaces.

Skin has strong self-regenerative capacity, while severe skin defects do not heal without appropriate treatment. Therefore, in order to cover the wound sites and hasten the healing process, wound dressings are required. Hydrogels have emerged as one of the most promising candidates for wound dressings because of their hydrated and porous molecular structure. Chitosan (CS) with biocompatibility, oxygen permeability, hemostatic and antimicrobial properties is beneficial for wound treatment and it can generate self-healing hydrogels through reversible crosslinks, from dynamic covalent bonding, such as Schiff base bonds, boronate esters, and acylhydrazone bonds, to physical interactions like hydrogen bonding, electrostatic interaction, ionic bonding, metal-coordination, host-guest interactions, and hydrophobic interaction. Therefore, various chitosan-based self-healing hydrogel dressings have been prepared in recent years to cope with increasingly complex wound conditions. This review\'s objective is to provide comprehensive information on the self-healing mechanism of chitosan-based hydrogel wound dressings, discuss their advanced functions including antibacterial, conductive, anti-inflammatory, anti-oxidant, stimulus-responsive, hemostatic/adhesive and controlled release properties, further introduce their applications in the promotion of wound healing in two categories: acute and chronic (infected, burn and diabetic) wounds, and finally discuss the future perspective of chitosan-based self-healing hydrogel dressings for wound healing.

In this study, we report observations of propagating radial carpet beams (RCBs) through a turbulent atmosphere at ground level with a 120 m path length. RCBs are a class of nondiffracting, accelerating, self-healing, and self-amplifying beams, and generated in the diffraction of a plane wave from amplitude/phase radial gratings having different spoke numbers. Observations were made at different times of the day. The intensity profile of an RCB becomes complicated when the number of grating spokes used to generate the beam is large, and includes high intensity spots, called main intensity spots (MISs), which are symmetrically placed at the central area around the beam axis and whose number is equal to (twice) the number of spokes of the amplitude (phase) grating used to generate the beam. With the aid of a telescope and a CCD camera, successive frames of the intensity pattern of the RCBs having different levels of structural complexity are recorded at the end of the path. For the data recorded at different times of the day, we calculate the variance of displacements of MISs along the radial direction. We observe that displacements of the MISs increase with increasing mean temperature of the air; on the other hand, as the complexity of the beam intensity pattern increases, the displacements of the MISs decrease. In order to compare the resilience of different RCBs and a well-known structured beam against atmospheric turbulence, we investigate deformation of the intensity profiles of a Laguerre-Gaussian (LG) beam having a topological charge 20 and different RCBs at the end of the path. It is shown that under the same turbulence condition, highly complex RCBs are more resilient to the destructive effects of the atmospheric turbulence. In particular, for the RCBs generated with gratings having 30 spokes and more, the number of MISs of the received intensity patterns is changed by less than 1% even when the turbulence strength is high. But for the LG beam, its intensity ring is clearly broken in different places, which makes it impossible to follow its maximum intensity in the radial direction.

Poly(urethane-urea) elastomers (PUUEs) have gained significant attention recently due to their growing demand in electronic skin, wearable electronic devices, and aerospace applications. The practical implementation of these elastomers necessitates many exceptional properties to ensure robust and safe utilization. However, achieving an optimal balance between high mechanical strength, good self-healing at moderate temperatures, and efficient flame retardancy for poly(urethane-urea) elastomers remains a formidable challenge. In this study, we incorporated metal coordination bonds and flame-retarding phosphinate groups into the design of poly(urethane-urea) simultaneously, resulting in a high-strength, self-healing, and flame-retardant elastomer, termed PNPU-2%Zn. Additional supramolecular cross-links and plasticizing effects of phosphinate-endowed PUUEs with relatively remarkable tensile strength (20.9 MPa), high elastic modulus (10.8 MPa), and exceptional self-healing efficiency (above 97%). Besides, PNPU-2%Zn possessed self-extinguishing characteristics with a limiting oxygen index (LOI) of 26.5%. Such an elastomer with superior properties can resist both mechanical fracture and fire hazards, providing insights into the development of robust and high-performance components for applications in wearable electronic devices.

Flexible and stretchable electronics rely on compliant conductors as essential building materials. However, these materials are susceptible to wear and tear, leading to degradation over time. In response to this concern, self-healing conductors have been developed to prolong the lifespan of functional devices. These conductors can autonomously restore their properties following damage. Conventional self-healing conductors typically comprise solid conductive fillers and healing agents dispersed within polymer matrices. However, the solid additives increase the stiffness and reduce the stretchability of the resulting composites. There is growing interest in utilizing gallium-based liquid metal alloys due to their exceptional electrical conductivity and liquid-phase deformability. These liquid metals are considered attractive candidates for developing compliant conductors capable of automatic recovery. This perspective delves into the rapidly advancing field of liquid metal-based self-healing conductors, exploring their design, fabrication, and critical applications. Furthermore, this article also addresses the current challenges and future directions in this active area of research.