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The human-machine interface (HMI) previously relied on a single perception interface that cannot realize three-dimensional (3D) interaction and convenient and accurate interaction in multiple scenes. Here, we propose a collaborative interface including electrooculography (EOG) and tactile perception for fast and accurate 3D human-machine interaction. The EOG signals are mainly used for fast, convenient, and contactless 2D ( XY -axis) interaction, and the tactile sensing interface is mainly utilized for complex 2D movement control and Z -axis control in the 3D interaction. The honeycomb graphene electrodes for the EOG signal acquisition and tactile sensing array are prepared by a laser-induced process. Two pairs of ultrathin and breathable honeycomb graphene electrodes are attached around the eyes for monitoring nine different eye movements. A machine learning algorithm is designed to train and classify the nine different eye movements with an average prediction accuracy of 92.6%. Furthermore, an ultrathin (90 μm), stretchable (∼1000%), and flexible tactile sensing interface assembled by a pair of 4 × 4 planar electrode arrays is attached to the arm for 2D movement control and Z -axis interaction, which can realize single-point, multipoint and sliding touch functions. Consequently, the tactile sensing interface can achieve eight directions control and even more complex movement trajectory control. Meanwhile, the flexible and ultrathin tactile sensor exhibits an ultrahigh sensitivity of 1.428 kPa -1 in the pressure range 0-300 Pa with long-term response stability and repeatability. Therefore, the collaboration between EOG and the tactile perception interface will play an important role in rapid and accurate 3D human-machine interaction.

High-performance electromagnetic interference (EMI) shielding materials with ultralow density, excellent flexibility, and good mechanical properties are highly desirable for aerospace and wearable electronics. Herein, honeycomb porous graphene (HPG) fabricated by laser scribing technology is reported for EMI shielding and wearable applications. Due to the honeycomb structure, the HPG exhibits an EMI shielding effectiveness (SE) up to 45 dB at a thickness of 48.3 μm. The single-piece HPG exhibits an ultrahigh absolute shielding effectiveness (SSE/t) of 240 123 dB cm 2 /g with an ultralow density of 0.0388 g/cm 3 , which is significantly superior to the reported materials such as carbon-based, MXene, and metal materials. Furthermore, MXene and AgNWs are employed to cover the honeycomb holes of the HPG to enhance surface reflection; thus, the SSE/t of the HPG/AgNWs composite membrane can reach up to 292 754 dB cm 2 /g. More importantly, the HPG exhibits excellent mechanical stability and durability in cyclic stretching and bending, which can be used to monitor weak physiological signals such as pulse, respiration, and laryngeal movement of humans. Therefore, the lightweight and flexible HPG exhibits excellent EMI shielding performance and mechanical properties, along with its low cost and ease of mass production, which is promising for practical applications in EMI shielding and wearable electronics.

Abstract A quasi-isostatic pressing technique for encapsulating spherical high-temperature inorganic phase change materials (PCMs) was presented in this work. To enhance the thermal conductivity of PCMs, graphite powder was dispersed into the PCM pellets. Meanwhile, cellulose particles, as sacrificial particles, were mixed with the PCM pellets to relieve the volumetric expansion of the PCMs during the phase change process. The effects of the latent heat, thermal conductivity, and thermal expansion behavior of the PCM/graphite capsule were investigated. The PCM capsules were able to work at temperatures up to 900 °C, including undergoing a solid-liquid phase change at 803 °C with a latent heat of 159.6 J g−1, and survived more than 300 thermal cycles as thermal energy storage devices. The thermal performance of the PCM capsules between 500 and 900 °C was numerically investigated using a modified one-dimensional (1-D) enthalpy-based model. The results indicated that the average heat transfer of the PCM capsules with graphite-dispersed core was significantly elevated during both the charging (by 92.5% for 99% charge) and discharging (by 168.4% for 99% discharge) processes, compared to the pure core PCMs. Highlights • Encapsulation of high-temperature inorganic phase change materials using graphite as heat transfer enhancer was presented. • The PCM capsules had a solid-liquid phase change at 803 °C (159.6 J g−1) and could survive more than 300 thermal cycles. • The numerical results showed that the PCM/graphite performed a significantly enhanced average heat transfer. [ABSTRACT FROM AUTHOR]

Thermal energy storage is highlighted as a crucial strategy for energy saving and utilization, in which domain, latent heat storage using phase change materials has gained great potential for efficient heat storage and thermal management applications. A strategy for developing high energy-storage-density and power-density latent heat storage units, through the compression-induced assembly of expanded graphite based stearic acid composites and the macro encapsulation method by using polyethylene shells, is demonstrated. The fabricated composite shows a satisfactory phase change enthalpy of 161.24 ± 0.5 J g−1, and enhances thermal conductivity to 13.4 ± 0.8 W m−1 K−1. The resulting heat storage unit also exhibits form-stable, leakage-proof, good homogeneity, and high-power-density behaviors. A 0.462 kWh proof-of-concept prototype of the packed-bed latent-heat-storage system by using 492 heat storage units has demonstrated its feasibility in fast heat charging/discharging operations. The outlet air temperature in the discharging process can maintain above 30 °C for over 1.74 h with a heat storage utilization efficiency of 90.3 ± 6.1% and an effective discharging efficiency of 93.5 ± 9.4%, under a volumetric flow rate of 30 m3 h−1 and heat storage temperature of 27–86 °C. The maximum and average power density, and effective energy density are obtained as 20.7 ± 1.6 kW m−3, 14.2 ± 0.9 kW m−3, 24.8 ± 2.5 kWh m−3, respectively, with a discharging threshold temperature of 30 °C. This high-power-density apparatus using form-stable heat storage units has realized hourly rapid heat charging-discharging processes, showing its prospective potential of low-temperature heat storage and thermal management. • A compression-induced assembly and macro encapsulation method is developed to prepare phase-change heat storage units. • The fabricated EG-SA composite exhibits a satisfactory phase change enthalpy and enhanced thermal conductivity. • The resulting heat storage units show form-stable, leakage-proof, good homogeneity, and high-power-density behaviors. • A packed-bed latent-heat-storage prototype is demonstrated to realize hourly rapid heat charging and discharging processes. [ABSTRACT FROM AUTHOR]