CAREER: A Prosthetic Elbow with Network of Soft and Modular Thermo-Active Actuators for Mobility Impaired Patients

在美国，大约有1500万行动不便的人需要帮助来移动他们的四肢。辅助机器人已经被提出来帮助有行动障碍的人。现有的用于辅助机器人的致动器仅限于刚性致动器和软致动器。刚性驱动器是强大的，但可能会造成伤害。软致动器可以更安全，但不像刚性致动器那样强大，便携或响应。使用热来刺激致动的软致动器是便携式的并且可以是强大的。然而，它们的响应对于许多康复应用来说可能太慢。这个NSF教师早期职业发展（CAREER）项目试图通过开发用于康复的基于Peltier的柔性软致动器的新型网络来克服这些挑战。该项目将为未被充分代表的大学预科生、本科生和研究生以及残疾学生提供研究机会。PI的长期目标是创造一种轻便、便携、柔软但反应迅速且功能强大的可穿戴康复技术。为了实现这一目标，该项目旨在优化开发和控制模块化热激活软执行器网络，这些执行器具有前所未有的性能，可用于康复应用。每个致动器由两个模块组成，其中由于液-气相变引起的剧烈体积变化导致每个模块内的柔性管的轴向膨胀和收缩。柔性Peltier放置在模块之间，以从一个模块吸收热量并将热量传递到另一个模块。一个模块在加热时膨胀，另一个模块在冷却时膨胀。该提案的研究目标是：（1）理解底层的多物理（电-热-机械）控制致动器和网络的操作，（2）创建用于优化网络性能并建立致动器的设计参数对性能的影响的框架，（3）开发通用且鲁棒的控制方案，和（4）证明了拟议的网络致动器的能力，可用作假肢肘关节的传动系统。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

There are about 15 million mobility impaired people in the United States who need assistance to move their limbs. Assistive robots have been proposed to help people with mobility impairments. Existing actuators for assistive robots are limited to rigid actuators and soft actuators. Rigid actuators are powerful but may cause injury. Soft actuators can be safer, but not as powerful, portable, or responsive as their rigid counterparts. Soft actuators that use heat to stimulate actuation are portable and can be powerful. However, their response can be too slow for many rehabilitation applications. This NSF Faculty Early Career Development (CAREER) project attempts to overcome these challenges by developing novel networks of flexible Peltier-based soft actuators designed for rehabilitation. The project will provide research opportunities to underrepresented pre-college, undergraduate, and graduate students and to students with disabilities.The PI’s long-term goal is to create a wearable rehabilitation technology that is lightweight, portable, and soft but also quick to respond and powerful. Toward this goal, this project aims to optimally develop and control networks of modular thermo-active soft actuators with unprecedented properties for rehabilitation applications. Each actuator is composed of two modules, in which dramatic volume change due to the liquid-gas phase transitions leads to the axial expansion and contraction of a flexible tube inside each module. Flexible Peltiers are placed between modules to absorb heat from one module and to deliver heat to the other module. One module expands when heated, and the other one expands when cooled. The research objectives of the proposal are to: (1) understand the underlying multi-physics (electro-thermo-mechanical) governing the operation of the actuator and the network, (2) create a framework for optimizing the network performance and establishing the effect of the actuator’s design parameters on the performance, (3) develop a versatile and robust control scheme, and (4) demonstrate the capabilities of the proposed networked actuators to be used as a drivetrain for a prosthetic elbow.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.