Soft Lego-like interlocking metasurfaces for modular soft robotics

Modular soft robots offer an alternative to conventional rigid robotic systems due to their adaptability, resilience, and potential for low-cost manufacturing. By creating systems from reconfigurable units, soft robots can adapt their morphology to different tasks, navigate unstructured environments, and recover from local failure through module replacement. Such capabilities are particularly valuable in applications such as search and rescue, where versatility and adaptability are critical.

A key limitation in current modular soft robot design lies in how the modules are connected: existing modular soft robotic systems often rely on rigid connectors or magnetic interfaces. While effective for attachment, these interface-joining solutions can introduce localized stiffness and geometric constraints that undermine the inherent compliance of soft robots, limiting maneuverability and performance in complex environments.

This project aims to introduce soft interlocking metasurfaces (ILMs) as a new class of compliant connectors for modular soft robotics. ILMs are architected arrays of interlocking features that, similar to Legos™, enable non-permanent attachment, conferring adhesive properties to adjoining surfaces. Soft ILMs are composed of inflatable bladders that expand within a mating interface to create mechanical interference, creating attachment that is both reversible and with localized tunable stiffness.

We hypothesize that soft ILMs can achieve the dual requirement of compliance and structural robustness, creating strong yet deformable attachments between soft robotic modules. To test this hypothesis, this project will focus on integrating soft ILMs into an existing modular platform, the Origamienabled Soft Crawling Autonomous Robot (OSCAR), which currently uses magnetic connections. Replacing these interfaces with ILM-based joints will enable direct comparison of strength, compliance, and system-level performance.

In this project, we will:

  1. Design and fabricate soft ILMs based on inflatable, interference-based mechanisms
  2. Design actuation and valving strategies for ILM arrays
  3. Integrate them into the OSCAR platform
  4. Experimentally evaluate joint strength and robot maneuverability

Beyond demonstrating feasibility, this project aims to establish a new design paradigm for modular soft robotic interfaces. By embedding compliance directly within the attachment mechanism, soft ILMs can enable robots to better exploit continuous deformation, improving locomotion in complex environments and enhancing robustness in real-world environments.