T-phage inspired piezoelectric microrobot

T-phages use contractile tails to recognize host bacterial and move on the surface of bacterial. This virus demonstrates remarkable locomotive capabilities in recognition and infection progress. The field of microrobotics focuses on achieving these functions in mobile robotic systems of centimeter size. However, owing to the structure size and weight, it has been a challenge to satisfy high robustness, fast motion, adequate carrying capacity, low driving voltage, and versatile environmental adaptability in one robot. In addition, functional microrobots require multimodal locomotive strategies that reconcile the constraints imposed by different applications. Inspired by the unique structure of T-phage in the micro-world, we develop a T-phage Mimic MicroRobot (TMMR), which is composed of a triangular prism core with piezoelectric elements and legs attached on bases, mimicking the core and the tail fibers of the T-phage, respectively. The triangular prism structure avoids rollover while moving, indicating the robustness of the design. TMMR of 2.5 × 2.5 × 2.6 mm³ weighs 1.74 gs and can be easily further miniaturized. It is capable of moving forward, backward, and steering at a low voltage of 25 V. Working mechanisms for each type of motion are analyzed using the finite element method. Results show that TMMR reaches 120 mm/s, 4.8 body lengths per second (BL/s), and carry an object weighing 10.6 gs, 6 times more than its weight. By sealing the body and adding passive flaps, TMMR achieves a “swimming” motion with a velocity of 16 mm/s. TMMR shows potential for versatile applications in a narrow and constrained environment.