Low Spring Index NiTi Coil Actuators for Use in Active Compression Garments
Name
Newman_Low Spring Index.pdf
Size
7 MB
Format
Adobe PDF
Checksum (MD5)
326959b0b1210afe7243a6761c40c7a0
Author(s)
Holschuh, Bradley T.
Obropta, Edward W.
Newman, Dava
Date Issued
June 2014
Journal
IEEE/ASME Transactions on Mechatronics
Publisher
Institute of Electrical and Electronics Engineers (IEEE)
Citation
Holschuh, Bradley, Edward Obropta, and Dava Newman. “Low Spring Index NiTi Coil Actuators for Use in Active Compression Garments.” IEEE/ASME Transactions on Mechatronics (2014): 1–14.
Version
Author's final manuscript
Abstract
This paper describes the modeling, development, and testing of low spring index nickel titanium (NiTi) coil actuators designed for use in wearable compression garments, and presents a prototype tourniquet system using these actuators. NiTi coil actuators produce both large forces (>1 N) and large recoverable displacements (>100% length) that are well suited for compression garment design. Thermomechanical coil models are presented that describe temperature and force as a function of nondimensionalized coil geometry, extensional strain, and applied voltage. These models suggest that low spring index coils maximize activation force, and an analytical model is presented to predict garment counter-pressure based on actuator architecture. Several low spring index (C = 3.08) coils were manufactured, annealed, and tested to assess their detwinning and activation characteristics. Results suggest both annealing and applied stress affect activation thresholds. Actuator force increases both with extensional strain and applied voltage up to 7.24 N. A first-generation compression tourniquet system using integrated actuators with direct voltage control of applied pressure is presented, demonstrating >70% increase in applied pressure during activation. This approach enables new, dynamic garments with controllable activation and low effort donning and doffing, with applications ranging from healthcare solutions to advanced space suit design.
MIT Department
Massachusetts Institute of Technology. Department of Aeronautics and Astronautics
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1109/TMECH.2014.2328519
