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Soft actuators are a new generation of robotic actuators designed for safer and more adaptable physical human-robot interaction, that can be triggered by various stimulating mechanisms, including pneumatic, electric, electromagnetic, light, magnetic, and thermal sources. Among the different types of soft actuators, thermoresponsive ones that utilize heat as the stimulus show great potential due to their ability to deliver a relatively high force-to-size ratio without the need for external air pumps, tethers, high voltage sources, or complex designs. However, a major drawback of such actuators is their limited bandwidth. Traditional methods rely on Joule heating for actuation, with the actuator deflating when the heat source is turned off and ambient temperature takes over. Recently, the Peltier mechanism has been introduced as an alternative approach for active heating and cooling. This research paper presents a comparative analysis of the Peltier and flexible heater mechanisms in terms of the bandwidth and energy consumption of phase-change thermo-active soft actuators. The study aims to assess the potential of Peltier-based actuation in addressing the bandwidth limitations observed in traditional soft actuators. The findings reveal that Peltier-based actuation can significantly improve actuation speed in thermoresponsive soft actuators. However, it is important to note that the performance of Peltier-based actuators decreases after a few cycles unless additional measures, such as the use of an external fan, are implemented. This increase in performance comes at the cost of higher energy consumption, which should be carefully considered in practical applications.
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3D Printed Gerotor Pump Geometries for Soft-Robot Actuation
Abstract Often, fluidic soft robots are driven by large pneumatic or low-bandwidth hydraulic systems which struggle to meet performance objectives. This research presents the design of two morphologies of compact, positive displacement hydraulic pumps designed to act as power supplies for fluidic soft robots. These hydraulic pumps were designed to leverage additive manufacturing technology, creating cost-effective, yet volumetrically powerful units. The operational bandwidth of these pumps (> 10Hz) was substantially higher than the natural frequency of most elastomer-based soft robots (1–5Hz), allowing high control authority. These designs allow for highly scalable pumps, with performance documented in the paper. Due to the 3D printed nature of the pump components, manufacture cost is greatly reduced when compared to machined components. Each was tested driving various soft robotic actuators, demonstrating high-bandwidth, yet precise operation. With their minimal size, these pumps are candidates for un-tethered mobile soft robots, and their low weight and low noise allows them to be carried on the body for robotic actuators used in mobility rehabilitation.
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- Award ID(s):
- 1935278
- PAR ID:
- 10480708
- Publisher / Repository:
- American Society of Mechanical Engineers
- Date Published:
- Journal Name:
- Proceedings of the ASMEBATH Symposium on Fluid Power and Motion Control
- ISSN:
- 2475-7004
- ISBN:
- 978-0-7918-8743-1
- Format(s):
- Medium: X
- Location:
- Sarasota, Florida, USA
- Sponsoring Org:
- National Science Foundation
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