Micro hexapod robots are desirable tools for exploring hazardous environments such as areas affected by natural disasters. Our objective is to reduce the cost of fabricating micro hexapod robots and contribute to their mass production. Conventionally, when the micro robot is assembled, it is necessary to handle, align, and assemble the micro parts, and these processes increase the fabrication cost. We propose a fabrication system in which the robot is assembled from one compliant sheet fabricated using MEMS processes. This method can streamline the processes of handling and aligning the micro parts. The joint element of the robot is composed of a compliant hinge, and the joints are driven by shape memory alloy (SMA) actuators. In this study, we assembled a hexapod robot from one compliant sheet fabricated by the MEMS processes. Furthermore, SMA actuators were attached to the robot, and testing of the joints was performed.

In recent years, micro robots have been actively studied for swarm applications. For example, micro hexapod robots have remarkable mobility on rough terrains. To apply micro hexapod robots in swarm explorations, the fabrication costs of the robots must be reduced. In this study, we propose a hexapod robot for swarm applications, assembled from a single flexible printed circuit (FPC) sheet. The necessary components for swarm applications (the body frame, legs, micro actuators, walking linkages, driving circuits, and microcontroller) are integrated into one FPC sheet. Our robot is assembled by folding one FPC sheet, and eliminating the need to handle and align multiple components during assembly. Thus, the robot can be fabricated cost effectively in short time. Moreover, we perform a driving test of the walking linkage and a walking test of the hexapod robot to demonstrate its effectiveness.

Recently, micro walking robots have attracted considerable research interest, as they can move robustly in various terrains and are especially useful in swarm applications. To realize angle control for the robots, external sensors such as rotary encoders were attached to joints. When assembling external sensors and joint components, careful handling and positioning are needed. However, robots requiring intricate assembly of multiple components are not optimal for the above-mentioned applications. We proposed the integration of robot frames and capacitive angle sensors to one compliant sheet. Moreover, a stacked electrostatic angle sensor was developed by alternately folding two ribbon electrodes. The angle was estimated from the capacitance based on the distance between the electrodes. The sensor was designed and fabricated. Furthermore, we constructed the angle feedback control system using the proposed sensor. Feedback control within the range of 0° to 30° could be realized.

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