This work develops a fluidic soft robotic eel which combines the adaptability of soft material and the flexibility of eel-shaped body together. The soft eel-like robot consists of multiple soft actuation segments each of which is capable of bidirectional bending by two embedded symmetrical fluidic chambers. Propulsion will be produced when proper control rules are applied to the bending angles of the actuation segments. Robot design, prototype fabrication and system integration are described step by step. A motion controller based on central pattern generator (CPG) is designed for the soft eel-like robot by using identified parameters. Substantial experiments are implemented to evaluate the performance of the prototype. It is shown that the soft eel-like robot can flexibly perform linear motion and turning motion. Moreover, the soft eel-like robot keeps good continuity even when the parameters of the CPG-based controller changes. In general, the experimental results verify the effectiveness of the design and control methods for the soft eel-like robot, which provides a potential candidate to underwater exploration with limited space.

After the discovery of endogenous dinitrosyl iron complexes (DNICs) as a potential biological equivalent of nitric oxide (NO), bioinorganic engineering of [Fe(NO)₂] unit has emerged to develop biomimetic DNICs [(NO)₂Fe(L)₂] as a chemical biology tool for controlled delivery of NO. For example, water-soluble DNIC [Fe₂(μ-SCH₂CH₂OH)₂(NO)₄] (DNIC-1) was explored for oral delivery of NO to the brain and for the activation of hippocampal neurogenesis. However, the kinetics and mechanism for cellular uptake and intracellular release of NO, as well as the biocompatibility of synthetic DNICs, remain elusive. Prompted by the potential application of NO to dermato-physiological regulations, in this study, cellular uptake and intracellular delivery of DNIC [Fe₂(μ-SCH₂CH₂COOH)₂(NO)₄] (DNIC-2) and its regulatory effect/biocompatibility toward epidermal cells were investigated. Upon the treatment of DNIC-2 to human fibroblast cells, cellular uptake of DNIC-2 followed by transformation into protein-bound DNICs occur to trigger the intracellular release of NO with a half-life of 1.8 ± 0.2 h. As opposed to the burst release of extracellular NO from diethylamine NONOate (DEANO), the cell-penetrating nature of DNIC-2 rationalizes its overwhelming efficacy for intracellular delivery of NO. Moreover, NO-delivery DNIC-2 can regulate cell proliferation, accelerate wound healing, and enhance the deposition of collagen in human fibroblast cells. Based on the in vitro and in vivo biocompatibility evaluation, biocompatible DNIC-2 holds the potential to be a novel active ingredient for skincare products.