Microfluidic-based artificial muscles and method of formation
Inventors
Kartalov, Emil P. • Scherer, Axel
Assignees
California Institute of Technology • US Department of Navy
Publication Number
US-11060511-B1
Publication Date
2021-07-13
Expiration Date
2039-06-14
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Abstract
Artificial muscles comprising a body of dielectric elastomer, wherein the body contains a pair of microfluidic networks are presented. Each microfluidic network includes a plurality of channels fluidically coupled via a manifold. The channels of the microfluidic networks are interdigitated and filled with conductive fluid such that each set of adjacent channels functions as the electrodes of an electroactive polymer (EAP) actuator. By using the manifolds as compliant wiring to energize the electrodes, artificial muscles in accordance with the present disclosure mitigate some or all of the reliability problems associated with prior-art artificial muscles.
Core Innovation
The invention presents artificial muscles comprising a body of dielectric elastomer that incorporates a pair of microfluidic networks filled with conductive fluid. These networks each include multiple channels interconnected via a manifold. The interdigitated channels of the microfluidic networks function as electrodes of an electroactive polymer actuator, with the conductive-fluid-filled manifolds serving as compliant wiring to energize the electrodes.
The problem addressed is the unreliability and complexity of prior art artificial muscles, especially those using electroactive polymer actuators. Conventional electrostatic actuators are difficult to fabricate in volume, are complicated, unreliable due to poor-quality flexible electrodes, and require complex interconnections. Prior technologies like electromagnetics, pneumatics, thermal actuators, and shape-memory alloys have drawbacks such as bulkiness, slow actuation, high power consumption, and manufacturing challenges.
The present disclosure overcomes these issues by embedding electrically conductive microfluidic networks into a resilient dielectric elastomer body, providing robust, flexible, and reliable compliant electrodes and wiring. This configuration facilitates high-volume manufacturability using methods like 3D printing or photolithography. The combination of microfluidics and dielectric elastomer enables monolithic, sturdy artificial muscles capable of delivering and tolerating higher stresses, greater force, and improved reliability compared to prior art devices.
Claims Coverage
The patent includes two main independent claims covering artificial muscles formed by dielectric elastomer bodies with embedded microfluidic electrodes and manifolds filled with conductive fluid, and a method for forming such muscles.
Artificial muscle with embedded interdigitated microfluidic electrodes and manifolds
An artificial muscle comprising a body of dielectric elastomer incorporating first and second pluralities of interdigitated channels that are fluidically coupled to respective first and second manifolds. Each manifold and its channels are filled with electrically conductive fluid, arranged such that applying a voltage differential produces an attractive force between adjacent channels.
Arrangement of microfluidic networks and dielectric members generating compressive forces
An artificial muscle comprising first and second microfluidic networks filled with electrically conductive fluid, together with dielectric elastomer members arranged such that channels from both networks are interdigitated and each dielectric member lies between adjacent channels. Applying a voltage differential induces compressive forces on each dielectric member.
Method for forming an artificial muscle with embedded microfluidic networks
A fabrication method involving forming a dielectric elastomer body containing two microfluidic networks—each including plural interdigitated channels and manifolds fluidically coupled. The networks are filled with electrically conductive fluid, enabling voltage differential application across the networks to generate electrostatic actuation.
The claims cover artificial muscles formed of dielectric elastomer bodies containing interdigitated microfluidic channels and manifolds filled with conductive fluid that act as compliant electrodes and wiring. The voltage-driven attractive forces between channel electrodes induce actuation. The method claim covers the fabrication process of such muscles, emphasizing the structure and filling of microfluidic networks.
Stated Advantages
Conductive-fluid-filled channels provide highly reliable compliant electrodes for electrostatic actuators.
Conductive-fluid-filled manifolds act as flexible, robust wiring, preventing disconnection issues common with conventional wires.
Embedding microfluidic networks within the muscle body eliminates the need for separate dielectric components and hard electrodes, simplifying fabrication.
The structure enables high-volume manufacturing techniques such as 3D printing, photolithography, and replication molding, facilitating mass production.
Monolithic muscle fibers formed using this approach are sturdier and more robust than heterogeneous prior art stacks, allowing greater force delivery and tolerance of higher stresses before failure.
Documented Applications
Electrostatic actuators suitable for use in exoskeletons, prosthetics, and vehicle propulsion.
Acoustically quiet propulsion systems for underwater vehicles employing biomimetic muscle structures.
Artificial muscle fibers and bundles capable of biomimetic force generation for walking robots and wearable electronic devices.
Sphincter-like artificial muscles that provide constriction forces useful for peristaltic pumps or other fluidic actuation applications.
Biomimetic prosthetic or exoskeletal limbs mimicking the structure and function of biological muscles, enabling improved range of motion and intuitive use.
Biomimetic propulsion for unmanned underwater and surface vehicles using fish fin-like muscle arrangements for energetic efficiency and low acoustic signature.
Muscles mimicking large walking animals for optimized land locomotion, useful in ground vehicles with enhanced mobility and resilience against damage.
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