Biomimetic Robots Inspired by Annelid Animals: Research Progress and Development Trend

Annelid-inspired robots exhibit excellent motion adaptability and structural compliance, enabling them to navigate confined, hazardous, or complex environments such as pipelines, soil, or the gastrointestinal tract. This review summarizes key developments in their bionic part design, actuation methods, material selection, and performance characteristics. Comparative analyses show that different actuation strategies (e.g., pneumatic, shape memory alloys, and electroactive polymers, etc.) need to be weighed in terms of their advantages, limitations, and applicable environments. Materials like silicone rubber and SMA are evaluated for their strength, flexibility, and energy performance. Quantitative benchmarks of velocity, load capacity, and energy consumption are presented to highlight design-performance correlations. Prospective research directions include the integration of multifunctional adaptive materials, real-time feedback sensing systems, and scalable architectures for autonomous operation in unstructured environments.