Computational Design and Fabrication of Modular Robots with Untethered Control

Authors

Manas Bhargava ¹
Takefumi Hiraki ^2,3
Malina Strugaru ¹
Michal Piovarci ^1,4
Chiara Daraio ⁵
Daisuke Iwai ⁶
Bernd Bickel ^1,4

Affiliations

ISTA ¹
UofTs ²
CMV ³
ETH ⁴
CAL ⁵
UofOs ⁶

(* Joint Last authors)

Publication

Arxiv (under submission)

Abstract

Natural organisms utilize distributed actuation through their musculoskeletal systems to adapt their gait for traversing diverse terrains or to morph their bodies for varied tasks. A longstanding challenge in robotics is to emulate this capability of natural organisms, which has motivated the development of numerous soft robotic systems. However, such systems are generally optimized for a single functionality, lack the ability to change form or function on demand, or remain tethered to bulky control systems. To address these limitations, we present a framework for designing and controlling robots that utilize distributed actuation. We propose a novel building block that integrates 3D-printed bones with liquid crystal elastomer (LCE) muscles as lightweight actuators, enabling the modular assembly of musculoskeletal robots. We developed LCE rods that contract in response to infrared radiation, thereby providing localized, untethered control over the distributed skeletal network and producing global deformations of the robot. To fully capitalize on the extensive design space, we introduce two computational tools: one for optimizing the robot’s skeletal graph to achieve multiple target deformations, and another for co-optimizing skeletal designs and control gaits to realize desired locomotion. We validate our framework by constructing several robots that demonstrate complex shape morphing, diverse control schemes, and environmental adaptability. Our system integrates advances in modular material building, untethered and distributed control, and computational design to introduce a new generation of robots that brings us closer to the capabilities of living organisms.

Citation

@misc{bhargava2025computationaldesignfabricationmodular,
    title={Computational Design and Fabrication of Modular Robots with Untethered Control}, 
    author={Manas Bhargava and Takefumi Hiraki and Malina Strugaru and Yuhan Zhang and Michal Piovarci and Chiara Daraio and Daisuke Iwai and Bernd Bickel},
    year={2025},
    eprint={2508.05410},
    archivePrefix={arXiv},
    primaryClass={cs.RO},
    url={https://arxiv.org/abs/2508.05410},}

Acknowledgements

The authors express gratitude to Magali Lorion for assisting in the initial fabrication of LCEs, Pengbin Tang for providing the code for simulating discrete elastic rods, the Imaging and Optics Facility at ISTA for assisting with the spectrometry measurements, and the MIBA machine shop at ISTA for their support in manufacturing various devices.Funding: This project was supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (Grant Agreement No. 715767 -– MATERIALIZABLE).