Fast contracting artificial muscle and other hot materials

寻找的仪器是一台热成像摄像机。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。其中一种人造肌肉是由尼龙钓鱼线组成的，它被扭曲成螺旋状的线圈。当加热和冷却时，它会大量收缩和膨胀。它的长度通常会变化20%，与我们自己的肌肉相似。它可以在比我们的肌肉大100倍的力量下运作。结合使用低成本的现成材料，具有比我们自己的肌肉执行更多工作的能力-同等重量和体积-使得这些超卷曲尼龙致动器在医疗设备中具有吸引力，并作为汽车和管道中重型电磁阀的替代品，以及其他事物。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梯度力，并允许可变刚度。然而，这些材料的致动性在某些方面还没有得到很好的理解或需要进一步的发展，这阻碍了致动器的更广泛应用。一是当负载增加时，盘绕的螺纹会拉伸。这种一次性拉伸是可逆的，因此当负载被移除时它就会消失，但是在负载变化的情况下操作执行器是一项挑战，比如在与弹簧对抗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理解这种形状记忆效应。我们还想提高驱动速度。目前，执行器通常需要几秒钟才能做出响应。在头发直径四分之一的细丝中，最快的大冲击响应约为5赫兹。我们怎样才能在不过热和损坏设备的情况下让这个设备更快呢？热像仪也能帮上忙。其他应用也将使用热像仪，包括由导电聚合物制成的快速微致动器的开发，用于机器人应用的智能传感皮肤的生产，芯片加热的识别，了解油墨沉积的机制，观察体外感觉细胞温度识别等等。

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.