Brain-machine interface (BMI) is a device that translates neuronal information into commands, which is capable of controlling external software or hardware, such as a computer or robotic arm. In consequence, the electrodes with desirable electrical and mechanical properties for direct interacting between neural tissues and machines serves as the crucial and critical part of BMI technology. Nowadays, the development of material science provides many advanced electrodes for neural stimulating and recording. Particularly, the widespread applications of nanotechnologies have innovatively introduced biocompatible electrode that can have similar characteristics with neural tissue. This paper reviews the existing problems and discusses the latest development of electrode materials for BMI, including conducting polymers, silicon, carbon nanowires, graphene, and hybrid organic-inorganic nanomaterials. In addition, we will inspect at the technical and scientific challenges in the development of neural electrode for a broad application of BMI with focus on the biocompatibility, mechanical mismatch, and electrical performance of electrode materials.

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It is crucial to prepare wearable devices with high stretchability to reduce the mechanical mismatch when attached to the skin. Recently, pure polysaccharide‐based hydrogels have been intensively focused on due to the living matter‐like softness, abundance, inherent biocompatibility, complete biodegradability, and renewability. However, it remains a significant challenge to achieve pure polysaccharide‐based hydrogels with high stretchability. Herein, a facile strategy is presented to synthesize a highly stretchable hydrogel wearable patch by integrating the starch (from lotus rhizome) as skeleton and sodium chloride as the electrolyte, exhibiting several advantages such as low modulus (≈4.4 kPa), broad stretching range (0≈790%), high ionic conductivity (10 S m−1), high linearity (0.996, 0≈300%), and good reproducibility (>1000 cycles). Surprisingly, both stretchability and softness have surpassed those of other pure polysaccharide‐based hydrogels reported in the literature. Furthermore, the combination of the adhesion, the low modulus, and stretchability can realize conformal attachment to different kinds of uneven objects, including the skin. Based on these properties, an electrooculographic (EOG) signal acquisition system and a relevant prototype video game using starch hydrogel patches are designed, exhibiting great potential in EOG signals monitoring as well as human–machine interaction. Moreover, other functions such as biocompatibility and biodegradability are demonstrated.

A simple protocol has been developed for recycling plastic tissue culture vessels. The killing properties of microwaves were used to decontaminate plastic tissue culture vessels for reuse. Nine bacterial cultures, four gram-negative and five gram-positive genera, including two Bacillus species, were used to artificially contaminate tissue culture vessels. The microwaves produced by a "home-type" microwave oven (2.45 gHz) were able to decontaminate the vessels with a 3-min exposure. The same exposure time was also used to completely inactivate the following three test viruses: polio type 1, parainfluenza type 1 (Sendai), and bacteriophage T4. The recycling procedure did not reduce the attachment and proliferation of the following cell types: primary chicken and turkey embryo, HEp-2, Vero, BGMK, and MK-2.

Device–body interface is significant for acquiring high quality bio‐signals, preventing skin‐irritation, and minimizing the motion artifacts. However, low breathability of the typical substrate used in a flexible electronic device usually deteriorates the stability of device–body interface, which is imperative for long‐term application but commonly disregarded. In paper, a directional sweat transport and breathable electrode with three‐layer sandwiched structure is reported. The top hydrophilic hydrolyzed‐polyacrylonitrile (HPAN) layer and middle hydrophobic thermoplastic‐polyurethane (TPU) layer form Janus structure; and the bottom layer is an electrode layer of Ag nanowires (AgNWs). This dedicatedly designed electrode can transport sweat from skin to the top HPAN layer, while keeping low noise electrocardiogram (ECG) signal detection. In the trial of ECG monitoring, the results show that the electrode can achieve reliable recording with high signal noise rate (SNR) both in calm state (10.5 dB) and sweaty state (10.1 dB) with sweat tolerance. No allergy or obvious SNR degeneration is observed when utilizing the electrode owing to the effective sweat transport away from the device–body interface rather than accumulation. Finally, the application of the anti‐sweat accumulating electrode in wearable electronics is demonstrated.