SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4476-1
Self-sustained oscillation in soft actuators enables autonomous, untethered robotic locomotion, yet existing light-driven systems suffer from low oscillation frequencies, rapid photothermal degradation, and reliance on external controllers. This work presents a bat-inspired soft robot that converts continuous near-infrared (NIR) irradiation into sustained rotational motion via a coiled MXene-based liquid crystal elastomer (LCE) actuator. The actuator integrates Ti3C2Tx MXene nanosheets as photothermal converters within an LCE matrix, achieving a photothermal conversion efficiency of 78.3% and a steady-state temperature of 142 °C under 1.5 W cm−2 NIR (808 nm). The coil geometry induces a self-shadowing effect that generates periodic light exposure, producing autonomous oscillation at 2.7 Hz with an amplitude of 45°. The robot demonstrates a rotational speed of 120 rpm and a specific power density of 3.2 W kg−1, outperforming previously reported light-driven oscillators by a factor of 2.5. Under continuous operation for 10,000 cycles, the actuator retains 92% of its initial oscillation amplitude, with a degradation rate of 0.008% per cycle. The bat-inspired wing morphology enables directional rotation and obstacle avoidance in confined spaces. This platform eliminates the need for external modulation, offering a scalable route to autonomous soft robotics for inspection, environmental monitoring, and micro-manipulation.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025111403
Sediments from the Hengyang reach of the Xiangjiang River were analyzed for concentrations, chemical fractions, and sources of 14 heavy metals (As, Se, Cd, Sb, Pb, Tl, Bi, Co, Ni, Mn, Zn, V, Cr, Cu). Mean concentrations of As, Se, Cd, Sb, Pb, Tl, and Bi exceeded local background values, with Cd, Se, Bi, and As showing pronounced enrichment. Spatial heterogeneity was marked, with higher levels downstream; overall concentrations were lower than previously reported. Sequential extraction revealed that Sb, Bi, Se, Tl, Cu, As, V, Cr, and Ni were predominantly in the residual fraction (F4), while Zn, Cd, Pb, and Mn had higher extractable fractions (F1+F2+F3), with bioavailable fractions generally elevated downstream. Geo-accumulation index (Igeo) indicated no contamination by Co, Zn, V, or Cr, but varying degrees of contamination by Mn, Ni, As, Se, Cd, Sb, Pb, Tl, Bi, and Cu, with pollution severity order: Se>Cd>Bi>As>Sb>Pb>Tl>Ni>Cu>Mn>Zn>Cr>Co>V. Enrichment factors showed significant enrichment for Cd, Sb, and Bi, moderate for Pb, and low for others. Potential ecological risk index (RI) revealed Cd as the primary contributor (87.49% of total risk), with overall moderate risk at downstream sites and slight risk across the entire section. Source apportionment using PCA and PMF identified three sources: industrial and traffic mixed source (57.60%), natural source (16.00%), and industrial-natural mixed source (26.40%). These findings enhance understanding of heavy metal pollution mechanisms in the Hengyang section and recommend priority control of industrial and traffic emissions, with focus on Cd mobility, to support sediment remediation strategies.