Smart Artificial Muscles (SAM): Lightweight, soft self-powered actuators to assist mobility

Case ID:

Smart Artificial Muscles (SAM): Light-weight, Soft Self-Powered Actuators to Assist Mobility

WSU Tech#:  15-1281

Technology Summary:

All of the individual components of the proposed technology already exist; thus, there are no unique composition of matter IP to pursue for these components.  The novelty and invention lies in the integration of all of these components into a single unit.  This new design, using the known components, creates a new technology that is expected to outperform any of the current exoskeletons under development.


Key Aspects of the technology:


Smart artificial Muscle (SAM) is a lightweight, self-powered, polymer-nanocomposite (Dielectric Elastomer) based actuator, integrated with energy harvesting capability and high energy flexible lithium batteries.  This device generates its own power through energy harvesting and storage to generate adequate forces alongside weaker muscle to assist with joint movements.


The potential uses for SAM are as follows:

1.       Military: Assist soldiers with carrying heavy loads, walk greater distances and limit fatigue.  Would also decrease muscular/skeletal injuries.

2.       Prevents MSI and has uses in the rehabilitation of neurological injuries.  The devise also offloads the strain on muscle to decrease fatigue and give damaged muscle more of a chance to heal.

3.       For injuries such as brain injury, spinal cord injury and stroke, the device can provide needed external muscle force to assist with complex movements.  This would reduce the need for assistance and allow for independent mobility.

4.       An individual that can only perform limited movements can, over time, perform more complex movements.

5.       Would assist in the promotion of neuroplasticity, allowing the brain to reorganize neural pathway and allow movements to be activated through new pathways.  This would be useful in patients suffering from stroke, brain injury, etc.


The following are the primary attributes possible for this technology over currently marketed technologies:


1.            Actuation


The invention is looking to replace dielectric elastomers for the actuation of the carbon nanofibers which, once activated, contract like real muscle.  This dielectric elastomer has low permittivity and hence requires high voltage electrical circuits to control the energy and energy harvesting.  Part of the technology proposal is to replace the dielectric elastomer with silicone dielectrics which are currently under development through the use of ceramic fillers such as barium titanate and titanium dioxide, or elastomer blends such as such as polyurethane and silicone or through temporary electrical modification using corona charging poling can be employed to provide greater performance.  Currently soft polymers such as dielectric elastomers can tear due to very large strains.  Further research into innovative material fabrication is needed to improve the durability of soft polymeric materials, for which grant proposals have been sought (see Future Directions section, Studies and Funding subsection).


2.            Continuity of Movement


The device with embedded SAM generates an external moment M around a joint over which the individual wears the device.  If this additional external moment is timed during muscle contraction so as to augment the internal moment created by the muscle, it can significantly offload the force that the muscle has to provide in order to perform the movement.  This has 2 important consequences.  First it can ensure that the muscle experiences less tensile forces during contraction, thereby reducing the incidence of muscular/skeletal injury.  Second, if a muscle is weaker and does not produce the required force to generate the movement for functional activities, the hybrid device with embedded SAM can augment that force production, so that the individual can independently perform the functional task, hence improving both the life quality and independence.  In both of these scenarios, the onset of muscle fatigue is delayed and therefore the individual can perform the task longer, which gives the individual wearing the hybrid device with SAM an added advantage.


3.            Energy Harvesting


By harvesting the energy of natural movement, converting it to energy and then storing it, the device can have far greater utility before needing to change or charge the battery system.


4.            Flexible Batteries


Allows for greater comfort and freedom of movement over hard battery packs.


Competitive Advantages


Currently Regranex is the only prescription gel that accelerates the healing of diabetic ulcer, and it is only approved for diabetic ulcers from neuropathic incidence.  This new formulation may be a potent treatment for diabetic ulcers either on its own or in combination with Regranex.  This provides a large market opportunity with little competition.


Benefit Analysis:


An issue with the current systems that are enhancing movement, currently on or making their way to the market, is that they provide power through machine generators or powered exoskeletons.  These powered orthoses are designed to actuate particular joints with an aim to assist an individual to perform at home or in the community.  Two reviews have pointed out that there is small, but substantial evidence supporting the use of robotic powered exoskeletons in the recovery of functions.  The issue is that these bulky devices have the several critical disadvantages and are limited in their terms of size, weight and rigidity.  This adds significant energy expenditure and burden to the wearer and there is limited utility due to the need to recharge the batteries often.  Many of these issues are alleviated, as discussed previously.

This technology has 2 general commercial markets, at least at this stage of development.  These markets are for soldier enhancement, which is of interest to the military and orthotic rehabilitation.  Other markets may present themselves as the technology advances but these are the 2 clear markets of interest.

Stage of Development: Research


Patent Status:


Through the Office of Technology Commercialization at Wayne State University, we have filed an extensive and detailed patent application to the USPTO office. This is a detailed methods application with both specific and fairly broad claims.


Licensing Opportunity:

WSU is looking for commercial partners interested in furthering the validation of this technology and bringing the technology to market.  The inventors would be open to assist in the generation of SBIR/STTR grants to fund the further development of this technology.

Patent Information:
For Information, Contact:
John Shallman
Wayne State University
Leela Mohana Arava
Sujay Galen
Heather Lai
Chin Tan