Fast contracting artificial muscle and other hot materials

寻找的仪器是热成像摄像机。它将用于捕获聚合物人造肌肉的加热和冷却，以及其他应用。这些人造肌肉之一是由尼龙钓鱼线，是扭曲，直到它形成一个螺旋线圈。当加热和冷却时，它会大量收缩和膨胀。它通常会改变20%的长度，类似于我们自己的肌肉。它可以在比我们的肌肉大100倍的力下运作。使用低成本现成材料的组合，具有执行比我们自己的肌肉更多的工作的能力-对于相同的重量和体积-使得这些超螺旋尼龙致动器在医疗设备中的使用具有吸引力，并且作为汽车和管道中重型电磁阀的替代品。这些线可以织成织物。像肌肉一样，它们可以并行操作以产生分级的力，并允许可变的刚度。然而，这些材料的致动的一些方面还没有很好地理解或需要进一步的发展，并且这些阻碍了致动器的更广泛的应用。一种是当载荷增加时，盘绕的螺纹拉伸。这一次拉伸是可逆的，因此当负载被移除时它会消失，但这使得在负载变化的条件下操作致动器变得具有挑战性-例如对抗弹簧工作或拾取和放置物体时。我们对为什么会发生这种情况有一些想法，并将使用热摄像机来了解这种形状记忆效应。我们还希望提高驱动速度。此时，致动器通常需要几秒钟才能做出响应。最快的大行程响应是大约5 Hz的细丝，其直径是头发的四分之一。我们怎样才能使这个设备更快，而不过热和损坏它？热成像摄像机会有帮助。其他应用也将使用热成像相机，包括开发由导电聚合物制成的快速微致动器，生产用于机器人应用的智能传感皮肤，识别芯片加热，了解墨水沉积的力学，观察体外感觉细胞温度识别等。

The instrument sought is a thermal imaging video camera. It will be used to capture the heating and cooling of polymer artificial muscles, among other applications. One of these artificial muscles consists of nylon fishing line that is twisted until it forms a helical coil. When heated and cooled it contracts and expands by a large amount. It typically changes length by 20 %, similar to our own muscle. And it can operate under about 100 times more force per area than our muscle. The combination of using low cost readily available materials, with the ability to perform a lot more work than our own muscle - for an equivalent weight and volume - makes these supercoiled nylon actuators attractive for use in medical devices, and as replacements for heavy solenoid valves in automobiles and plumbing, among other things. These threads can be woven into fabrics. Like muscle, they can be operated in parallel to produce graded forces, and to allow variable stiffness. However some aspects of the actuation of these materials are not well understood or need further development, and these are holding back more widespread application of the actuators. One is that the coiled threads stretch when load is increased. This one time stretch is reversible, so it disappears when the load is removed, but it makes it challenging to operate the actuator under conditions where load is changing - like when working against a spring, or picking and placing an object. We have some ideas on why this is happening, and will use a thermal video camera to understand this shape memory effect. We also want to increase speed of actuation. At the moment it typically takes a few seconds for the actuator to respond. The fastest large stroke response is about 5 Hz in filaments that are a quarter the diameter of a hair. How can we make this device faster, without overheating and damaging it? Again the thermal camera will help. Other applications will also use the thermal camera sought, including the development of fast micro actuators made from conducting polymers, production of smart sensing skins for robotic applications, identification of on chip heating, understanding the mechanics of ink deposition, observing sensory cell temperature recognition in vitro and more.