Antibacterial adhesive injectable hydrogels with rapid self-healing, extensibility and compressibility as wound dressing for joints skin wound healing.

Recent progress in electronic skin or e-skin research is broadly reviewed, focusing on technologies needed in three main applications: skin-attachable electronics, robotics, and prosthetics. First, since e-skin will be exposed to prolonged stresses of various kinds and needs to be conformally adhered to irregularly shaped surfaces, materials with intrinsic stretchability and self-healing properties are of great importance. Second, tactile sensing capability such as the detection of pressure, strain, slip, force vector, and temperature are important for health monitoring in skin attachable devices, and to enable object manipulation and detection of surrounding environment for robotics and prosthetics. For skin attachable devices, chemical and electrophysiological sensing and wireless signal communication are of high significance to fully gauge the state of health of users and to ensure user comfort. For robotics and prosthetics, large-area integration on 3D surfaces in a facile and scalable manner is critical. Furthermore, new signal processing strategies using neuromorphic devices are needed to efficiently process tactile information in a parallel and low power manner. For prosthetics, neural interfacing electrodes are of high importance. These topics are discussed, focusing on progress, current challenges, and future prospects.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.201904765

Electronic Skin: Recent Progress and Future Prospects for Skin‐Attachable Devices for Health Monitoring, Robotics, and Prosthetics

Self-healing is the capability of a material to recover from physical damage. Both physical and chemical approaches have been used to construct self-healing polymers. These include diffusion and flow, shape-memory effects, heterogeneous self-healing systems, covalent-bond reformation and reshuffling, dynamics of supramolecular chemistry or combinations thereof. In this Review, we discuss the similarities and differences between approaches to achieve self-healing in synthetic polymers, where possible placing this discussion in the context of biological systems. In particular, we highlight the role of thermal transitions, network heterogeneities, localized chemical reactions enabling the reconstruction of damage and physical reshuffling. We also discuss energetic and length-scale considerations, as well as scientific and technological challenges and opportunities. Self-healable polymers are materials that recover after physical damage. In this Review, we discuss the physical and chemical approaches to make self-healing polymers, with a focus on similarities with biological systems.

Self-healing polymers

Biological systems have the powerful ability to self-heal. Human skin can, for example, autonomously heal from wounds of various degrees, allowing it to restore its mechanical and electrical properties. In contrast, human-made electronic devices degrade over time due to fatigue, corrosion or damage incurred during operation, leading to device failure. Self-healing chemistry has emerged in recent years as a promising method for constructing soft electronic materials that are mechanically robust and can self-repair. Here we review the development of self-healing electronic materials and examine how such materials can be used to fabricate self-healing electronic devices. We explore the potential new functionalities of self-healing electronic systems that would not typically be possible with conventional electronic systems and discuss the current challenges in delivering self-healing soft electronics for practical applications. This Review Article examines the development of self-healing electronic materials and devices, explores their potential applications and discusses the challenges that exist in delivering practical systems.

Self-healing soft electronics

Covalent polymers connected by non-covalent interactions constitute a fascinating set of materials known as supramolecular polymer networks (SPNs). A key feature of SPNs is that the underlying covalent polymers endow the resulting self-assembled materials with features, such as structural and mechanical integrity, good processability, recyclability, stimuli-responsiveness, self-healing, and shape memory, that are not recapitulated in the case of classic covalent polymer systems. The unique nature of SPNs derives from the controlled marriage of traditional covalent polymers and macrocycle-based host-guest interactions. As a consequence, supramolecular polymeric networks have played important roles in a number of diverse fields, including polymer science, supramolecular chemistry, materials science, biomedical materials, and information storage technology. In this Review, we summarize advances made in the area of functional SPNs, with a focus on original literature reports appearing in the past five years. The treatment is organized according to the key macrocycle-based host-guest interactions used to produce various SPNs. The role of the underlying polymer backbones is also discussed.

Functional Supramolecular Polymeric Networks: The Marriage of Covalent Polymers and Macrocycle-Based Host-Guest Interactions

The ability to monitor blood flow is critical to patient recovery and patient outcomes after complex reconstructive surgeries. Clinically available wired implantable monitoring technology requires careful fixation for accurate detection and needs to be removed after use. Here, we report the design of a pressure sensor, made entirely of biodegradable materials and based on fringe-field capacitor technology, for measuring arterial blood flow in both contact and non-contact modes. The sensor is operated wirelessly through inductive coupling, has minimal hysteresis, fast response times, excellent cycling stability, is highly robust, allows for easy mounting and eliminates the need for removal, thus reducing the risk of vessel trauma. We demonstrate the operation of the sensor with a custom-made artificial artery model and in vivo in rats. This technology may be advantageous in real-time post-operative monitoring of blood flow after reconstructive surgery.

Biodegradable and flexible arterial-pulse sensor for the wireless monitoring of blood flow

Herein, we report a de novo chemical design of supramolecular polymer materials (SPMs-1–3) by condensation polymerization, consisting of (i) soft polymeric chains (polytetramethylene glycol and tetraethylene glycol) and (ii) strong and reversible quadruple H-bonding cross-linkers (from 0 to 30 mol %). The former contributes to the formation of the soft domain of the SPMs, and the latter furnishes the SPMs with desirable mechanical properties, thereby producing soft, stretchable, yet tough elastomers. The resulting SPM-2 was observed to be highly stretchable (up to 17 000% strain), tough (fracture energy ∼30 000 J/m2), and self-healing, which are highly desirable properties and are superior to previously reported elastomers and tough hydrogels. Furthermore, a gold, thin film electrode deposited on this SPM substrate retains its conductivity and combines high stretchability (∼400%), fracture/notch insensitivity, self-healing, and good interfacial adhesion with the gold film. Again, these properties are all ...

/pdf/quadruple-h-bonding-cross-linked-supramolecular-polymeric-55jk1dq2gk.pdf

Junheng Li

Papers

Biodegradable and flexible arterial-pulse sensor for the wireless monitoring of blood flow

Quadruple H-Bonding Cross-Linked Supramolecular Polymeric Materials as Substrates for Stretchable, Antitearing, and Self-Healable Thin Film Electrodes

Polymers in Lithium-Ion and Lithium Metal Batteries

CT-derived radiomic analysis for predicting the survival rate of patients with non-small cell lung cancer receiving radiotherapy.