Hernando-García Jorge, García-Caraballo Jose Luis, Ruiz-Díez Víctor, Sánchez-Rojas Jose Luis
Microsystems, Actuators and Sensors Group, Universidad de Castilla-La Mancha, E-13071 Ciudad Real, Spain.
Micromachines (Basel). 2020 Mar 20;11(3):321. doi: 10.3390/mi11030321.
This article reports on the locomotion performance of a miniature robot that features 3D-printed rigid legs driven by linear traveling waves (TWs). The robot structure was a millimeter-sized rectangular glass plate with two piezoelectric patches attached, which allowed for traveling wave generation at a frequency between the resonant frequencies of two contiguous flexural modes. As a first goal, the location and size of the piezoelectric patches were calculated to maximize the structural displacement while preserving a standing wave ratio close to 1 (cancellation of wave reflections from the boundaries). The design guidelines were supported by an analytical 1D model of the structure and could be related to the second derivative of the modal shapes without the need to rely on more complex numerical simulations. Additionally, legs were bonded to the glass plate to facilitate the locomotion of the structure; these were fabricated using 3D stereolithography printing, with a range of lengths from 0.5 mm to 1.5 mm. The optimal location of the legs was deduced from the profile of the traveling wave envelope. As a result of integrating both the optimal patch length and the legs, the speed of the robot reached as high as 100 mm/s, equivalent to 5 body lengths per second (BL/s), at a voltage of 65 V and a frequency of 168 kHz. The blocking force was also measured and results showed the expected increase with the mass loading. Furthermore, the robot could carry a load that was 40 times its weight, opening the potential for an autonomous version with power and circuits on board for communication, control, sensing, or other applications.
本文报道了一种微型机器人的运动性能，该机器人具有由线性行波驱动的3D打印刚性腿。机器人结构是一块毫米级的矩形玻璃板，上面附着有两个压电片，这使得在行波产生时，其频率介于两个相邻弯曲模式的共振频率之间。作为首要目标，计算了压电片的位置和尺寸，以在保持驻波比接近1（消除边界处的波反射）的同时最大化结构位移。该设计准则得到了结构的一维解析模型的支持，并且可以与模态形状的二阶导数相关，而无需依赖更复杂的数值模拟。此外，腿被粘结到玻璃板上以促进结构的运动；这些腿是使用3D立体光刻打印制造的，长度范围为0.5毫米至1.5毫米。腿的最佳位置是根据行波包络的轮廓推导出来的。由于集成了最佳的片长和腿，在65V电压和168kHz频率下，机器人的速度高达100mm/s，相当于每秒5个身体长度（BL/s）。还测量了阻塞力，结果表明其随质量负载的增加符合预期。此外，该机器人能够承载其重量40倍的负载，为带有用于通信、控制、传感或其他应用的电源和电路的自主版本开辟了潜力。
