Elastic Inflatable Actuators for Soft Robotic Applications

Abstract

The 20th century's robotic systems have been made from stiff materials, and much of the developments have pursued ever more accurate and dynamic robots, which thrive in industrial automation, and will probably continue to do so for decades to come. However, the 21st century's robotic legacy may very well become that of soft robots. This emerging domain is characterized by continuous soft structures that simultaneously fulfill the role of robotic link and actuator, where prime focus is on design and fabrication of robotic hardware instead of software control. These robots are anticipated to take a prominent role in delicate tasks where classic robots fail, such as in minimally invasive surgery, active prosthetics, and automation tasks involving delicate irregular objects. Central to the development of these robots is the fabrication of soft actuators. This article reviews a particularly attractive type of soft actuators that are driven by pressurized fluids. These actuators have recently gained traction on the one hand due to the technology push from better simulation tools and new manufacturing technologies, and on the other hand by a market pull from applications. This paper provides an overview of the different advanced soft actuator configurations, their design, fabrication, and applications.

Soft Robotic Grippers

“…For more details of performance on the actuation, controlled stiffness, and adhesion technology, see refs. and Sections…”

“…FEAs (also referred to as soft pneumatic actuators) are among the oldest but still today the most widespread actuation technologies for soft robotics due to a number of advantages, including easy fabrication, robustness, and low cost elastomer materials . Actuation is obtained through the pressure exerted by a fluid (liquid or gas) on a chamber made by highly deformable materials (Figure c).…”

Remotely Light‐Powered Soft Fluidic Actuators Based on Plasmonic‐Driven Phase Transitions in Elastic Constraint

“…Consequently, novel soft actuation strategies are sought, with boosted functionality in the elastic regime and capable of being fabricated and combined with soft structures . One of the most versatile strategies of actuating soft robots is fluidic actuation . Tailoring the structural anisotropy of the flexible actuators pressurized by gasses or liquids enables expansion, bending, twisting, and contracting motion while reducing overall complexity to a minimum—an elastic structure and a pressure source .…”

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pumps, pressurized gas containers, combustion, chemical reactions, and phase transitions. [6,[9][10][11] Often rigid and bulky components of classic fluidic circuits (such as bulky valves, tubes, and pumps tethered to the devices) are necessary and untethering is still a big challenge in soft robotics with fluidic actuation. [2,9,[12][13][14][15] New materials with embodied functionality capable of actuation provide essential potential for further developing soft robotic systems such as light-driven systems that enabling not only untethering but also drastically reducing complexity by providing integrated functionality.

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“…[4][5][6] Tailoring the structural anisotropy of the flexible actuators pressurized by gasses or liquids enables expansion, bending, twisting, and contracting motion while reducing overall complexity to a minimum-an elastic structure and a pressure source. [6] This actuation strategy is realized in nature and the plant kingdom by varying turgor pressures and water flux [7,8] In soft robotics, the pressure variation causing expansion of an elastic structure is obtained by www.advmat.de www.advancedsciencenews.com efficient enough to drive various centimeter-scale soft robotic structures validating broad applicability. Figure 1A shows the concept of the remotely light-powered actuation: laser irradiation heats metallic NPs at plasmon resonance dispersed in a liquid-phase that is encapsulated in an elastomeric casing.…”