Low Spring Index NiTi Coil Actuators for Use in Active Compression Garments
Low Spring Index NiTi Coil Actuators for Use in Active Compression Garments
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DOI：
10.1109/tmech.2014.2328519
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发表时间：
2015-06-01
影响因子：
6.4
通讯作者：
Newman, Dava
中科院分区：
文献类型：
--
作者：
Holschuh, Bradley;Obropta, Edward;Newman, Dava
本文介绍了低弹簧指数镍钛（NiTi）线圈致动器设计用于可穿戴压缩服装的建模，开发和测试，并提出了一个原型止血带系统使用这些致动器。NiTi线圈致动器产生大的力（> 1N）和大的可恢复位移（>100%长度），这非常适合于压缩服装设计。热机械线圈模型，描述温度和力的函数的无量纲线圈的几何形状，拉伸应变，和施加的电压。这些模型表明，低弹簧指数线圈最大限度地提高激活力，并提出了一个分析模型来预测服装反压力的基础上致动器架构。制造了几个低弹簧指数（C = 3.08）弹簧圈，对其进行退火和测试，以评估其去孪晶和激活特性。结果表明，退火和施加应力影响激活阈值。致动器力随着拉伸应变和施加电压的增加而增加，最高可达7.24 N。第一代压缩止血带系统采用集成致动器，具有施加压力的直接电压控制，证明在激活期间施加压力增加>70%。这种方法使新的，动态的服装与可控的激活和低努力穿脱，与应用范围从医疗保健解决方案，以先进的航天服设计。
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.