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Modern development of flexible electronics has made use of bioelectronic materials as artificial tissue in vivo. As hydrogels are more similar to nerve tissue, functional hydrogels have become a promising candidate for bioelectronics. Meanwhile, interfacing functional hydrogels and living tissues is at the forefront of bioelectronics. The peripheral nerve injury often leads to paralysis, chronic pain, neurologic disorders, and even disability, because it has affected the bioelectrical signal transmission between the brain and the rest of body. Here, a kind of light-stimuli-responsive and stretchable conducting polymer hydrogel (CPH) is developed to explore artificial nerve. The conductivity of CPH can be enhanced when illuminated by near-infrared light, which can promote the conduction of the bioelectrical signal. When CPH is mechanically elongated, it still has high durability of conductivity and, thus, can accommodate unexpected strain of nerve tissues in motion. Thereby, CPH can better serve as an implant of the serious peripheral nerve injury in vivo, especially in the case that the length of the missing nerve exceeds 10 mm.

Lithium dendrite related problems form a major barrier that limits the application of lithium metal anode for Li-ion batteries. Here a copper coated 3D soft fabric anode was developed to show superior battery performance under an optimized mechanical stress for the lithium metal anode application. A scalable two-step dip-coating method was applied to coat Cu onto various insulating cloth fabrics, making them electrically conductive. In our battery tests, the 3D soft conductive fabric contributes to a more uniform lithium deposition during the battery cycling, which works for more than 1000 h. The mechanism for suppressing lithium dendrite growth by the mechanical interaction with 3D Cu-fabric was also revealed by a combination of microscopy characterization, electrochemical test and theoretical modeling, which provides the design principle for their future applications in lithium metal anode batteries.

The rapid growth of miniaturized electronic devices has raised the demand for compact, flexible, wearable, and non-volatile memory units. However, integration into nanoelectronic devices requires a scaled-down data-storage component, but this often results in the deterioration of the ferroelectric switching performance. Herein, we demonstrate a simple and scalable fabrication of poly (vinylidene fluoride trifluoroethylene) [P(VDF-TrFE)] film with graphene oxide (GO) nanosheets. Using piezoresponse force microscopy (PFM), the storage features of this multilayer film were investigated, including establishment of two stable memory states, ferroelectric switching dynamics in the point-polarization and linear-polarization modes, and time and thermal stability of information storage. Remarkably, the GO-P(VDF-TrFE) film favored formation of low-temperature (LT) ferroelectric phase with much more ordered sequences of trans conformations relative to pristine P(VDF-TrFE) due to the presence of electrostatic interaction between GO nanosheets and C F dipoles of P(VDF-TrFE), thus affording improved ferroelectric properties. The GO-P(VDF-TrFE) film showed several excellent storage features, such as ultra-high density of more than 300 Gbits in−2, good writing & erasing repeatability, long data retention time, and elevated device operation temperature. In-depth understanding and utilization of the excellent non-volatile memory performance of this new GO-ferroelectric system will open new avenues for the next generation of nanoelectronic devices.

The degeneration of dopaminergic neurons is a major contributor to the pathogenesis of mid-brain disorders. Clinically, cell therapeutic solutions, by increasing the neurotransmitter dopamine levels in the patients, are hindered by low efficiency and/or side effects. Here, a strategy using electromagnetized nanoparticles to modulate neural plasticity and recover degenerative dopamine neurons in vivo is reported. Remarkably, electromagnetic fields generated by the nanoparticles under ultrasound stimulation modulate intracellular calcium signaling to influence synaptic plasticity and control neural behavior. Dopaminergic neuronal functions are reversed by upregulating the expression tyrosine hydroxylase, thus resulting in ameliorating the neural behavioral disorders in zebrafish. This wireless tool can serve as a viable and safe strategy for the regenerative therapy of the neurodegenerative disorders.

Wireless micro- and nanorobots are biomedical devices with a potential use in high-precision minimally invasive therapies. Here, a highly integrated multifunctional soft microrobot is developed for targeted cell therapy applications, featuring targeted cell transportation and induced cell differentiation. The micromachines are made of composites consisting of a soft piezoelectric polymer matrix in which magnetic nanoparticles are dispersed. The magnetic nanoparticles serve as the component for the device's magnetic actuation, while the piezoelectric polymer acts as both a steerable scaffold and an acoustically responsive cell electrostimulation platform. With the application of a rotating magnetic field, the microrobots swim in a corkscrew motion in different liquid environments that mimic human body fluids. When the swimmers are subjected to acoustic waves, their piezoelectric body is electrically polarized which induces cell differentiation of neuron-like PC12 cells loaded on the swimmers surface. This combinatorial technique may open up new avenues for bioelectronic therapies., Materials Horizons, 6 (7)

Marine biofouling can be better governed by using super-hydrophobic and lubricant leaching behavior. It was prepared for a long time super-hydrophobic fouling release coating with the incorporation of phenylmethylsilicone oil as lubricant. With the reasonable control of the mass ratio of mixed nano-particles (hydroxylated multi-walled carbon nanotube and nano-magnetite), prepared reinforced coating has excellent super-hydrophobicity and lubricant leaching efficiency. Comparable studies with reported FR coating and commercial silicone coating, it exhibits excellent anti-biofilm adhesion performance with up to 98 % of biofilm adhesion removal rate. More beneficial, the isolation layer composed of the leached phenylmethylsilicone oil can make a good buffer effect for the reinforced coating surface, alleviating the deformation or damage caused by the friction between sand and the reinforced coating surface, effectively. This work is establishing new investments in environment-friendly fouling release coatings.

Ferroelectric polymers are of interest as most promising electroactive materials. Flexible transducers from ferroelectric polymer thin film with underneath semiconducting polymer active layer for high sensitive and versatile detection of physiological signals are described. When attached directly on the wrist, the flexible transducers can distinguish the transient pulse waves non-invasively and in situ, due to their fast response (milliseconds) and high sensitivity (down to several Pascal) to instantaneous change of blood pressure. High-resolution picture of one pulse wave is available to provide two most common parameters for arterial stiffness diagnosis. The transducers are also suitable for dynamic recognizing physiological signals under both physical exercise and medicine treatment, demonstrating their enormous potential for warning the risk of cardiovascular disease, and evaluating the efficacy of heart medicines. The transducers are easy to carry around with an operating voltage of 1 V and the power consumption less than 1 μW. Thus, they are valuable for applications like electronic skin and mobile health monitoring.

A multimodal cancer therapeutic nanoplatform is reported. It demonstrates a promising approach to synergistically regulating the tumor microenvironment. The combination of intracellular reactive oxygen species (ROS) generated by irradiation of photosensitizer and endoplasmic reticulum (ER) stress induced by 2-deoxy-glucose (2-DG) has a profound effect on necrotic or apoptotic cell death. Especially, targeting metabolic pathway by 2-DG is a promising strategy to promote the effect of photodynamic therapy and chemotherapy. The nanoplatform can readily release its cargoes inside cancer cells and combines the advantages of ROS-sensitive releasing chemotherapeutic drugs, upregulating apoptosis pathways under ER stress, light-induced generation of cytotoxic ROS, achieving tumor accumulation, and in vivo fluorescence imaging capability. This work highlights the importance of considering multiple intracellular stresses as design parameters for nanoscale functional materials in cell biology, immune response, as well as medical treatments of cancer, Alzheimer's disease, etc.

Through utilizing individual nanodots, as smallest memory units, to convert stress into readable electronic information, we report force-induced high-density data storage in the periodic nanostructure of ferroelectric polymer fabricated by nanoimprinting lithography. The nanostructure is ideal for the stress concentration and increasing the non-uniformity of strains, thus leading to strain gradients inversely proportional to the feature size. A force as low as 400 nN is applied to generate the internal electric field in response to strain gradients and switch polarization state of each memory unit. It can achieve storage density theoretically up to TB/inch2 with the up-to-date nanofabrication technology to miniaturize the unit size.