A bio-inspired co-simulation crawling robot enabled by a carbon dot-doped dielectric elastomer.

Flexible actuation materials play a crucial role in biomimetic robots. Seeking methods to enhance actuation and functionality is one of the directions in which actuators strive to meet the high-performance and diverse requirements of environmental conditions. Herein, by utilizing the method of adsorbing N-doped carbon dots (NCDs) onto SiO2 to form clusters of functional particles, a NCDs@SiO2/PDMS elastomer was prepared and its combined optical and electrical co-stimulation properties were effectively harnessed to develop a biomimetic crawling robot resembling Rhagophthalmus (firefly). The introduction of NCDs@SiO2 cluster particles not only effectively improves the mechanical and dielectric properties of the elastomer but also exhibits fluorescence response and actuation response under the co-stimulation of UV and electricity, respectively. Additionally, a hybrid dielectric elastomer actuator (DEA) with a transparent SWCNT mesh electrode exhibits two notable advancements: an 826% increase in out-of-plane displacement under low electric field stimulation compared to the pure matrix and the ability of NCDs to maintain a stable excited state within the polymer for an extended duration under UV-excitation. Simultaneously, the transparent biomimetic crawling robot can stealthily move in specific environments and fluoresce under UV light.

Correction: Efficient and stable electrorheological fluids based on chestnut-like cobalt hydroxide coupled with surface-functionalized carbon dots.

Correction for 'Efficient and stable electrorheological fluids based on chestnut-like cobalt hydroxide coupled with surface-functionalized carbon dots' by Yudai Liang et al., Soft Matter, 2022, DOI: 10.1039/D2SM00176D.

Efficient and stable electrorheological fluids based on chestnut-like cobalt hydroxide coupled with surface-functionalized carbon dots.

Intrinsically polarized electrorheological fluids (ERFs) have better thermal stability than ERFs with polar molecules, so they have a broader application prospect. However, the electrorheological efficiency of the common intrinsically polarized ERF is still lower than 1500, which is related to the poor wettability between polarized materials and the continuous phase. Carbon dots (CDs) exhibit good stability, semiconductor properties and low toxicity. We prepared biomimetic chestnut-like cobalt hydroxide coupled with surface-functionalized CD particles (Co(OH)2@CDs) by a simple hydrothermal method. Then we prepared an ERF by mixing Co(OH)2@CDs with silicone oil and studied the effect of CDs on its rheology and electrorheology properties. The synergistic effect of the lipophilic groups on the surface of CDs and the biomimetic chestnut-like structure makes Co(OH)2@CDs exhibit good wettability with silicone oil, and the optimal zero-field viscosity of Co(OH)2@CDs-ERF is only 0.46 Pa s (particle mass fraction of 40%). Exceptional electrorheological efficiency (about 10 000, shear rate 0.1 s-1, 5 kV mm-1) and dynamic shear stress stability of optimal Co(OH)2@CDs-ERF can be attributed to the dielectric enhancement of the biomimetic chestnut-like structure coupled with the semiconductor properties of CDs. In addition, Co(OH)2@CDs-ERF has excellent anti-settling performance, outstanding thermal stability and low current density.