Soft Robotic Actuators Using Gas-Generating Pressurizing Devices

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Solution Overview

Problem

Current robotic systems face limitations in mobility and versatility, particularly in constrained environments, due to their rigid structures and limited material selection, which hinders their ability to mimic the stable and efficient movement of soft-bodied organisms like Echinoderms and Cnidarians.

Innovation Solution

The development of untethered soft robotic devices that utilize pressurized gas sources, including electrolyzers and microcompressors, and explosive actuation mechanisms, such as combustion of combustible fluids, to enable flexible and efficient movement, allowing for complex motions and directional jumping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If rigid structures and traditional actuation methods are used, then structural strength and stability are improved, but mobility and versatility in constrained environments deteriorate

Engineering Contradiction:
Improvestructural strengthVSAvoidmobility in constrained environments
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The patent employs soft robotic actuators with flexible polymer bodies instead of rigid structures. The actuators use extensible polymer materials that can deform and adapt to constrained environments, enabling stable motility in spaces where traditional rigid robots would fail. This directly addresses the contradiction by replacing rigid structures with flexible ones that maintain sufficient strength while dramatically improving adaptability.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent utilizes pneumatic actuation systems with bellows and pressure vessels to provide controlled movement in soft robotic actuators. This pneumatic approach enables versatile motion control while maintaining structural integrity through pressure-based actuation, resolving the contradiction between strength and mobility in constrained environments.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Adaptability or versatility

If soft materials and new actuation mechanisms are used, then adaptability and mobility in constrained environments are improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvemobility in constrained environmentsVSAvoidactuation system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent divides the soft robotic system into modular components including separate pressure vessels, bellows actuators, and control systems. This segmentation allows each component to be optimized independently and simplifies manufacturing and assembly, reducing overall device complexity while maintaining high adaptability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces complex electromechanical actuation systems with pneumatic actuation using bellows and pressure vessels. This substitution simplifies the control mechanism while maintaining soft robotic functionality, reducing device complexity without compromising mobility in constrained environments.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If traditional hard-bodied robot designs are used, then manufacturing precision and structural integrity are improved, but weight and cost increase

Engineering Contradiction:
Improvestructural integrityVSAvoidrobot weight
Core Design Contradiction:
Manufacturing precisionVSWeight of moving object

Solution Approach 1:

The patent uses thin-walled pressure vessels and bellows made from extensible polymer materials that provide sufficient structural integrity while minimizing weight. These flexible shells maintain the necessary strength for actuation without the excessive weight of traditional metal components, directly addressing the weight-integrity tradeoff.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent employs composite polymer structures combining extensible and inextensible materials to achieve optimal strength-to-weight ratios. This composite approach provides necessary structural integrity for actuation while keeping the overall weight low, resolving the contradiction between manufacturing precision/integrity and weight.

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

These devices achieve stable and efficient movement in constrained spaces, with the ability to jump and navigate complex terrain, while being lighter and more cost-effective than traditional hard-bodied robots, leveraging the properties of soft materials and gas generation principles for actuation.

Implementation Method 1

the untethered pressurizing device comprises an electrolytic cell and the reagents are selected to provide a gas product during electrolysis

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Implementation Method 2

wherein the untethered pressurizing device comprises a gas-producing reagent selected to provide a gas in a thermal decomposition reaction

Methodology Applied
Scientific EffectThermal decomposition: Decomposition (biological)

Implementation Method 3

the resistive wire is configured to receive electric current

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 4

providing a pressurized fluid from the untethered pressurizing device to the fluid chamber in the flexible body

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 5

igniting the combustible fluids to produce a rapidly expanding gas

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP2764255B1Systems and methods for actuating soft robotic actuators
Publication Date: 2020.09.09 PRESIDENT & FELLOWS OF HARVARD COLLEGE
  • EP2764255B1 patent drawingFigure 1A~1C
  • EP2764255B1 patent drawingFigure 2
  • EP2764255B1 patent drawingFigure 3

AI summary

Systems and methods for providing a soft robot is provided. In one system, a robotic device includes a flexible body having a fluid chamber, where a portion of the flexible body includes an elastically extensible material and a portion of the flexible body is strain limiting relative to the elastically extensible material. The robotic device can further include a pressurizing inlet in fluid communication with the fluid chamber, and a pressurizing device in fluid communication with the pressurizing inlet, the pressurizing device including a reaction chamber configured to accommodate a gas-producing chemical reaction for providing pressurized gas to the pressurizing inlet.