RESUMEN
Insects and animals in nature generally have powerful muscles to guarantee their complex motion, such as crawling, running, and jumping. It is challenging for insect-sized robots to achieve controlled crawling and jumping within the scale of millimeters and milligrams. This article proposes a novelty bionic muscle actuator, where an electrical pulse is applied to generate joule heat to expand the actuator's chamber. Under the restoring force of the spring element, the chamber contracts back to the initial state to finish a complete cycle. The actuator can obtain high-frequency vibration under the high-frequency electrical signal. We propose a microrobot based on the novelty actuator to achieve controlled crawling and jumping over the obstacle of the millimeter-sized robot. The robot is fabricated with two actuators as a crawling module and one actuator as a jumping module, with a mass of 52 mg, length of 9.3 mm, width of 9.1 mm, and height of 4 mm. The microrobot has a maximum crawling turning velocity of 0.73 rad/s, a maximum jump height of 42 mm (10.5 times body height), and a maximum jump velocity of 0.91 m/s. This study extends the potential for applying the novelty bionic-muscle actuator to the microrobot.
RESUMEN
Limited by the surface-to-volume ratio of structural materials, it is a great challenge to achieve high output performance in a millimetre-sized actuator. Traditional rigid actuators can achieve higher vibration frequencies above the centimetre size, but their working performance will be greatly reduced below the millimetre size, and even cannot maintain the vibration. A micro-actuator is highly essential for the miniaturisation of bionic robots. In this work, we present a novel driving principle by utilising the plasmonic thermal energy generated by electric stimulation to drive the vibration of the micro-actuator. In the design, the micro-actuator is composed of two chambers and elastic elements, which is similar to the design of a micro-piston. By utilising the thermal energy of the plasma, the actuator can generate high-frequency vibration (resonant frequency of 140 Hz), and the simple structural design can achieve a large vibration amplitude on a millimetre scale. Based on this powerful actuator, several applications are presented, such as fast crawling and jumping. The good performance of the electric stimulus-responsive micro-actuator suggests promising applications ranging from millimetre-scale robots in confined spaces to detection, search and rescue.
RESUMEN
We report a novel electrostatic self-excited resonator driven by DC voltage that achieves variable velocity-position characteristics via applying the pre-tension/pre-compression constraint. The resonator consists of a simply supported micro-beam, two plate electrodes, and two adjustable constraint bases, and it can be under pre-compression or pre-tension constraint by adjusting the distance L between two constraint bases (when beam length l > L, the resonator is under pre-compression and when l < L, it is under pre-tension). The oscillating velocity of the beam reaches the maximum value in the position around electrodes under the pre-compression constraint and reaches the maximum value in the middle position between two electrodes under the pre-tension condition. By changing the constraint of the microbeam, the position of the maximum velocity output of the oscillating beam can be controlled. The electrostatic self-excited resonator with a simple constraint structure under DC voltage has great potential in the field of propulsion of micro-robots, such as active rotation control of flapping wings.