An artificial skeletal muscle for use in pediatric rehabilitation robotics
| Author(s) | Behboodi, Ahad | |
| Date Accessioned | 2020-02-27T12:17:21Z | |
| Date Available | 2020-02-27T12:17:21Z | |
| Publication Date | 2019 | |
| SWORD Update | 2020-02-03T13:29:53Z | |
| Abstract | Perceptual-motor experience is critical in early childhood for learning and cognition. By exploring object properties and relations among objects, infants develop visual-motor coordination, spatial skills, memory, language, cognition, and problem solving abilities. Such development and performance of activities of daily life (ADLs) rely heavily upon upper extremity function; and those with impaired reaching ability are at great risk for delays in these areas. While increasing user ADL independence, automated assistive devices may potentially increase the dose of interaction, which may enhance cognitive, social and motor development. ☐ Many actuator materials and devices are used to power automated assistive devices, however, in orthotics and prosthetics, the requirement for a “natural” look and feel, to make the artificial or assisted limb feel integrated with the body, is limited by current technology. Bulky, heavy, noisy electrical motors are typically used, which substantially reduce user compliance of powered orthoses. For greater acceptance of such devices, the desired requirements include: low weight, quiet operation, soft feel, and size and shape approximating that of a natural limb, with cost being an important factor. Dielectric elastomer actuators (DEAs) feature great promise in fulfilling these requirements. Nonetheless, so far only a few studies have attempted to explore rehabilitation applications, and at a very preliminary level. ☐ The overall goal of this dissertation is to develop a powered unilateral exoskeleton using a commercially available DEA that works as “artificial skeletal muscle”, and thereby, assess DEAs' capabilities and limitations to actuate rehabilitation robots. ☐ In Aim 1, by assessment of the state of soft actuators technology, Stacked Dielectric Elastomer was chosen to form an artificial skeletal muscle for actuating an upper extremity rehabilitation exoskeleton. This was accomplished through comparison of five novel groups of soft actuators: Coiled Nylon Fiber, Ethanol-Based Phase-Change, Poly Vinyl Chloride Gel, Stacked Dielectric Elastomer and Hydraulically Amplified Self-Healing Electrostatic. ☐ In Aim 2, the electro-mechanical properties of a commercially available CTsystems’ stacked DEA (CT-SDEA) were benchmarked. CT-SDEA observed properties were then compared with the reported values for mammalian skeletal muscle and performance metrics, such as its length-tension properties and force generation hysteresis were assessed. Thereby, an artificial skeletal muscle using multiple CT-SDEAs in series and parallel was configured. ☐ In Aim 3, the capability of adding proprioception to the configured artificial muscle was evaluated. This was done by measuring the length-dependent variation in capacitance of the CT-DEA, via a previously established length self-sensing technique. This length self-sensing technique then was added to an artificial muscle consisting of three CT-SDEAs in series. To mimic the muscle spindle’s function in mammalian skeletal muscle, the length modulation of the middle CT-SDEA was then sensed, while the artificial muscle was contracting. ☐ In Aim 4, the capability of the configured artificial muscle in actuation of a phantom upper extremity model’s elbow joint was assessed. Multiple artificial muscle configuration were tested to actuate the joint. The artificial muscle consisting a bundle of 3 myofibrils, each which containing five actuators in series, generated 22º of elbow flexion in the sagittal plane with 224 º/s angular velocity, under 1 N of tensile load. ☐ These results demonstrated CT-SDEAs’ potentials and limitations in rehabilitation applications. Using the benchmark testing results, appropriate assistive devices can be designed, which fit the capabilities of these versatile soft actuators. Further investigation is needed to assess CT-SDEAs capabilities in actuating joints with range of motion smaller than that of the elbow, such as ankle. | en_US |
| Advisor | Lee, Samuel C. K. | |
| Degree | Ph.D. | |
| Program | University of Delaware, Biomechanics and Movement Science Program | |
| DOI | https://doi.org/10.58088/trxb-qp48 | |
| Unique Identifier | 1142098495 | |
| URL | http://udspace.udel.edu/handle/19716/25064 | |
| Language | en | |
| Publisher | University of Delaware | en_US |
| URI | https://search.proquest.com/docview/2307785910?accountid=10457 | |
| Title | An artificial skeletal muscle for use in pediatric rehabilitation robotics | en_US |
| Type | Thesis | en_US |