TY - GEN
T1 - The Multi-material Actuator for Variable Stiffness (MAVS)
T2 - 2020 IEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2020
AU - Thalman, Carly M.
AU - Hertzell, Tiffany
AU - Debeurre, Marielle
AU - Lee, Hyunglae
N1 - Funding Information:
C. M. Thalman is funded by the National Science Foundation, Graduate Research Fellowship Program (NSF-GRFP) award #1841051. This work is funded by the Global Sport Institute of the adidas and Arizona State University (ASU) Global Sport Alliance.
Publisher Copyright:
© 2020 IEEE.
PY - 2020/10/24
Y1 - 2020/10/24
N2 - This paper presents the design of the Multi-material Actuator for Variable Stiffness (MAVS), which consists of an inflatable soft fabric actuator fixed between two layers of rigid retainer pieces. The MAVS is designed to be integrated with a soft robotic ankle-foot orthosis (SR-AFO) exosuit to aid in supporting the human ankle in the inversion/eversion directions. This design aims to assist individuals affected with chronic ankle instability (CAI) or other impairments to the ankle joint. The MAVS design is made from compliant fabric materials, layered and constrained by thin rigid retainers to prevent volume increase during actuation. The design was optimized to provide the greatest stiffness and least deflection for a beam positioned as a cantilever with a point load. Geometric programming of materials was used to maximize stiffness when inflated and minimize stiffness when passive. An analytic model of the MAVS was created to evaluate the effects in stiffness observed by varying the ratio in length between the rigid pieces and the soft actuator. A finite element analysis (FEA) was generated to analyze and predict the behavior of the MAVS prior to fabrication. The results from the analytic model and FEA study were compared to experimentally obtained results of the MAVS. The MAVS with the greatest stiffness was observed when the gap between the rigid retainers was smallest and the rigid retainer length was smallest. The MAVS design with the highest stiffness at 100 kPa was determined, which required 26.71 ± 0.06 N to deflect the actuator 20 mm, and a resulting stiffness of 1, 335.5 N/m and 9.1% margin of error from the model predictions.
AB - This paper presents the design of the Multi-material Actuator for Variable Stiffness (MAVS), which consists of an inflatable soft fabric actuator fixed between two layers of rigid retainer pieces. The MAVS is designed to be integrated with a soft robotic ankle-foot orthosis (SR-AFO) exosuit to aid in supporting the human ankle in the inversion/eversion directions. This design aims to assist individuals affected with chronic ankle instability (CAI) or other impairments to the ankle joint. The MAVS design is made from compliant fabric materials, layered and constrained by thin rigid retainers to prevent volume increase during actuation. The design was optimized to provide the greatest stiffness and least deflection for a beam positioned as a cantilever with a point load. Geometric programming of materials was used to maximize stiffness when inflated and minimize stiffness when passive. An analytic model of the MAVS was created to evaluate the effects in stiffness observed by varying the ratio in length between the rigid pieces and the soft actuator. A finite element analysis (FEA) was generated to analyze and predict the behavior of the MAVS prior to fabrication. The results from the analytic model and FEA study were compared to experimentally obtained results of the MAVS. The MAVS with the greatest stiffness was observed when the gap between the rigid retainers was smallest and the rigid retainer length was smallest. The MAVS design with the highest stiffness at 100 kPa was determined, which required 26.71 ± 0.06 N to deflect the actuator 20 mm, and a resulting stiffness of 1, 335.5 N/m and 9.1% margin of error from the model predictions.
KW - Soft Actuator Modeling
KW - Soft Robot Applications
KW - Soft Robot Materials and Design
KW - Wearable Robots
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U2 - 10.1109/IROS45743.2020.9341430
DO - 10.1109/IROS45743.2020.9341430
M3 - Conference contribution
AN - SCOPUS:85102404545
T3 - IEEE International Conference on Intelligent Robots and Systems
SP - 8694
EP - 8700
BT - 2020 IEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2020
PB - Institute of Electrical and Electronics Engineers Inc.
Y2 - 24 October 2020 through 24 January 2021
ER -