An Impulsive Force Generator as a Micro size Transportable Device

利用弹性材料的通卡屈曲特性，研制了一种微型脉冲动力发生器（微弹射器）。这是第一个利用蛋白质的旋转运动来储存弹性能量并将其作为运动学能量释放的成功例子。该装置由固定在盖子上的运动蛋白（f_1 - atp酶）和涂有微珠作为弹性材料的肌动蛋白束组成。肌动蛋白束呈闭环结构，长度约为10μm。肌动蛋白束的一端通过磁珠作为主动旋转接头与f_1 - atp酶固定，另一端通过末端微珠作为被动旋转接头将肌动蛋白束固定在盖盖上。利用该装置，可以利用F_1-ATPase的驱动转矩与外加的ATP和外加磁场转矩所产生的过卡屈曲产生的冲激力，以肌动蛋白束弯曲变形为主的弹性能量储存在肌动蛋白束中。因此，这是第一个成功地将蛋白质的旋转运动转化为不同的运动模式（通过屈曲）的例子。在一定条件下，微弹射器产生的加速度可达120μm^2/S以上，一个弹射器可产生数十次重复的卡通屈曲。

We have developed minimum micro-scale impulsive force generator (microcatapult) utilizing snap-through buckling of an elastic material. It is the first successful example to store the elastic energy and release it as kinematic energy by using a rotary motion of protein. The device consists of motor protein (F_1-ATPase) immobilized on a coverslip and actin bundle coated with microbeads as an elastic material. It has a closed loop structure of the actin bundle with the length of about 10μm. One end of the actin bundle is fixed with F_1-ATPase through a magnetic bead as an active rotary joint, and the other end of the actin bundle is fixed on the coverslip through a terminal microbead as a passive rotary joint. Using this device, elastic energy stored in the actin bundle mainly by bending deformation of it can be obtained as impulsive force utilizing snap-through buckling generated by the driving torque of F_1-ATPase with added ATP and an external magnetic field torque. As a result, this is the first success example to convert a rotary motion of protein into different motion mode (snap-through buckling). The acceleration generated by the proposed micro-catapult reached more than 120μm^2/S under a solution and dozens of repeated snap-through buckling could be obtained for one the assembled devices.