Background
Micro-jumping robots offer unique advantages in scenarios such as confined space exploration and post-disaster search and rescue. However, traditional designs have consistently faced two major bottlenecks. On one hand, actuators based on elastic energy storage mechanisms like springs struggle to accumulate sufficient energy for effective jumping when miniaturized, while their reset mechanisms incur additional energy losses. On the other hand, low-power actuators made from piezoelectric or dielectric materials reduce energy consumption but fail to deliver the explosive force required for jumping.
Nature offers inspiration for solving this challenge—small animals like locusts achieve jumping efficiency far surpassing artificial systems through powerful hind leg muscles. Previous attempts to build actuators using intact organisms or cultured muscle tissue faced limitations: the former was constrained by the unpredictability of biological nervous systems, while the latter suffered from insufficient explosive force and reliance on culture media for viability, preventing practical breakthroughs. Locusts actively shed their hind legs during emergency circumstances. These discarded appendages retain activity for hours without any processing and respond to electrical stimulation sensitively, making them ideal natural materials for developing bio-hybrid actuators.
Research Progress
The research team innovatively repurposed discarded locust hind legs into bio-hybrid muscle actuators. Through optimized electrical stimulation protocols and synergistic integration with artificial robotic systems, they achieved three core breakthroughs:
(1) The bio-hybrid jumping robot demonstrated remarkable leaping capabilities. By precisely regulating electrical stimulation parameters, the robot achieved dynamic jumps reaching up to 18 times its body length and 7 times its height—outperforming most synthetic actuators. The secret lies in the locust hind legs' innate muscular structure, which provides a natural biomechanical foundation for explosive leaps.
(2) The drive requires an ultra-low input power of just 0.03 mW, far below the 1000-4000 mW power consumption typical of conventional micro-jumping robots. This advantage stems from a unique energy supply model: external electrical signals serve solely as triggers, while the kinetic energy required for jumping primarily originates from biochemical energy stored within the muscle tissue. This enables energy conversion efficiency that far surpasses purely artificial systems.
(3) It exhibits high maneuverability. By adjusting the electrical stimulation time difference between the left and right hind leg actuators, it can execute turning jumps ranging from 4° to 63°, with a steering response latency of just 1.5 milliseconds—faster than the response of a living locust. Additionally, the robot possesses autonomous self-righting capabilities, enabling continuous jumping.
The innovation of this research lies not only in its technical breakthroughs in micro-jumping robots but also in establishing a novel paradigm that integrates artificial actuators with biological actuators. Compared to traditional artificial actuators, the bio-hybrid design fully leverages the inherent advantages of biological tissues, achieving an optimal balance between volume, weight, energy efficiency, and explosive force.
Research Perspectives
This research pioneers a novel technical pathway for overcoming performance bottlenecks in micro-smart devices through the innovative integration of bio-muscle and artificial actuators. Its core value lies in establishing a synergistic channel between biological inherent advantages and engineered controllability. Moving forward, this bio-hybrid actuation model holds dual potential: First, it enables further optimization of the “bio-muscle-artificial component” adaptation system. For instance, integrating biocompatible encapsulation materials could enhance the stability and lifespan of the drive system, granting bio-hybrid actuators more reliable operational capabilities in complex environments. On the other hand, this technological approach holds promise for expanding into the combined development of diverse biological muscles and artificial drive components. For instance, by leveraging the movement characteristics of different insect muscles and pairing them with artificial modules like micro-motors and piezoelectric elements, multifunctional micro-robots capable of jumping, crawling, and grasping could be developed. These would provide customized drive solutions for scenarios such as confined space exploration, precision medical delivery, and precision equipment inspection, while also establishing a new technical paradigm for designing low-power intelligent devices.
The complete study is accessible via DOI:10.34133/research.0943