Centimeter-scale robots have unique advances such as small size, light weight, and flexible motions, which exhibit great application potential in many fields. Notably, high integration and robustness are 2 key factors determining the locomotion characteristics and practical applications. "Although they have achieved certain advancements in miniaturization and motion performance, the presence of electromagnetic motors and transmission mechanisms prevents further miniaturization. There are still issues such as electromagnetic interference and wear of the transmission components." stated Gao et al. In recent years, the development of smart materials brings new drive and transmission approaches in the fields of small robots, providing promising solutions for the miniaturization. Some functional materials such as dielectric elastomer materials, shape memory alloy materials, magnetostrictive materials, and piezoelectric materials have been applied in the field of small robots. Therefore, centimeter-scale robots with high integration and strong robustness demonstrate potential for practical applications. "Here, we propose a novel centimeter-scale quadruped piezoelectric robot with high integration and strong robustness, which promises to bring new perspectives for the construction and application of centimeter-scale robots." emphasized the authors.
The author said this work mainly achieves 4 key advancements: (1) A new built-in actuation method is proposed, and a centimeter-scale tethered robot prototype (14.47 g, 70 mm × 13 mm × 15.8 mm) is designed. It achieves fast locomotion with a speed up to 47.38 BL/s, a high carrying capability of 28.96 times self-weight, and a high resolution of 0.33 μm. The robot can perform cross-scale movement from sub-micron (micro) to meter (macro) level; (2) The untethered centimeter-scale robot realizes the integration of actuation, control, communication, and power supply through the built-in integration method, ensuring all functional units are protected within the metal substrate of the piezo unit. It has a low startup voltage (10 V0-p) and an endurance time of 32 min; (3) After being stepped on by an adult human's full body weight (66.45 kg, over 3,500 times heavier than the robot), as well as enduring 3 consecutive drops and 2 kicks, the robot still operates normally and continues to move afterward, demonstrating exceptional robustness; (4) The robot with a sensor module achieves real-time image grayscale conversion, multi-object image capture, color block tracking, and object detection, exhibiting great potential for image sensing applications and modular expansion. The proposed new built-in actuation method and the built-in integration method provide a design reference for high integration and strong robustness in centimeter-scale robots.
Researchers propose a new built-in actuation method and a centimeter-scale compact robot prototype is designed. The proposed methods provide a design reference for miniaturization and strong robustness in centimeter-scale robot. Some possible future directions and challenges include the following: (1) Exploring more efficient built-in actuation methods and piezoelectric ceramic arrangements to improve the motion performance of the robot; (2) Try to integrate small functional modules, such as micro grippers, to achieve cross-scale applications with multiple positioning points, long distances, and micro-gripping capabilities; (3) Increase the robot's position feedback capability for more precise motion control.
Authors of the paper include Yu Gao, Jing Li, Jie Deng, Shijing Zhang, and Yingxiang Liu.
This work has been completed with the financial support of the National Natural Science Foundation of China under Grant Nos. 52225501 (Y.L.), 523B2040 (J.L.), and U23A20617 (Y.L.); in part by the Postdoctoral Science Special Foundation of Heilongjiang Province, China, under Grant No. LBH-TZ2410 (J.D.); and by the China Postdoctoral Science Foundation under Grant No. 2024M764168 (S.Z.).
The paper, "A Centimeter-Scale Quadruped Piezoelectric Robot with High Integration and Strong Robustness" was published in the journal Cyborg and Bionic Systems on Jul 22, 2025, at DOI: 10.34133/cbsystems.0340.
