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Abstract The advent of robotics in medicine has brought about a paradigm shift, enabling minimally invasive interventions for in-vivo practices. Pill-based robots, specifically designed at the millimeter scale, have emerged as a viable alternative to traditional endoscopic methods for gastrointestinal tract diagnostics and treatment. These millirobots, capable of navigating the complex and constrained environments of the human body, offer a significant advantage by enabling thorough visualization or targeted drug delivery in a single session without the need for sedation. We previously developed a novel deployable tensegrity robot, designed for gastrointestinal diagnostics and treatment, which addresses the limitations of conventional capsule endoscopes through its unique structure and locomotion mechanism. Tensegrity structures, characterized by a network of components in tension and compression, provide an innovative solution to the challenges of designing robots for in-vivo applications. Our millimeter-scale tensegrity robot leverages the inherent advantages of such structures — lightweight, high stiffness, and adaptability — to navigate through densely packed tissues and high-pressure environments within the GI tract. Inspired by the locomotion of earthworms, the movement mechanism of the robot enables efficient navigation and precise positioning, significantly reducing the risk of retention and ensuring patient safety. This paper investigates the design and fabrication process of the tensegrity robot, focusing on achieving a high folding ratio to facilitate its deployment as a pill-based robot. Through a comparison of the robot’s fabricated dimensions with the theoretical design, we evaluate the accuracy of the fabrication process, highlighting the potential of this innovative approach in transforming GI tract diagnostics and treatment. The deployment of such tensegrity-based millirobots marks a new era in medical devices, promising enhanced patient safety and comfort through non-invasive methods.
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Prototype Design and Manufacture of a Deployable Tensegrity Microrobot
Micro-, and milli-scale robots have been of great R&D interest, due to their ability to accomplish difficult tasks such as minimally invasive diagnosis and treatment for human bodies, and underground or deep-sea tests for environment monitoring. A good solution to this design need is a multi-unit deployable tensegrity microrobot. The microrobot can be folded to only 15% of its deployed length, so as to easily enter a desired working area with a small entrance. When deployed, the tensegrity body of the robot displays lightweight and high stiffness to sustain loads and prevent damage when burrowing through tightly packed tissues or high-pressure environments. In this work, topology, initial configuration and locomotion of a deployable tensegrity microrobot are determined optimally. Based on the design, a centimeter-scale prototype is manufactured by using a fused deposition modelling advanced additive manufacturing or 3-D printing system for proof of concept. As shown in experimental results, the deployable tensegrity microrobot prototype designed and manufactured can achieve an extremely high folding ratio, while be lightweight and rigid. The locomotion design, that mimics a crawling motion of an earthworm, is proved to be efficient by the prototype equipped with stepper motors, actuation cables, control boards and a braking system.
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- PAR ID:
- 10429971
- Date Published:
- Journal Name:
- ASME 2022 International Mechanical Engineering Congress and Exposition
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1115/IMECE2022-93929
