Core Viewpoint - The emergence of small centimeter-level robots is revolutionizing the robotics field, showcasing their ability to navigate tight spaces and perform tasks that larger robots cannot, while also being cost-effective for large-scale deployment [1] Group 1: Small Robots Advantages - Small centimeter-level robots can operate in industrial facilities, natural caves, and disaster debris, executing inspection and exploration tasks [1] - Their design utilizes cheaper materials and less quantity, making them economically efficient for mass deployment [1] Group 2: Challenges Faced by Small Robots - Small robots face hardware limitations due to size constraints, lacking sufficient perception, drive, and control resources, which affects their dynamic stability during movement [3] - The complexity and space occupation issues arise from multi-legged designs, while bipedal robots face greater challenges in miniaturization while maintaining stability and efficiency [3] Group 3: Zippy - The Smallest Bipedal Robot - Zippy, a 3.6 cm tall bipedal robot, is the smallest independent bipedal walking robot, inspired by the passive dynamic walker (PDW) concept [4][5] - Zippy can passively stand without drive, and it can turn, jump, and climb stairs, achieving a maximum speed of 25 cm/s, making it the fastest autonomous bipedal robot relative to its leg length [5] Group 4: Design and Engineering of Zippy - Zippy's design is based on the simpler Mugatu robot, following five critical design rules to ensure stability and feasibility [8] - The robot's structure consists of two rigid bodies, each with a leg and a curved foot, produced using 3D printing, which simplifies the design and reduces manufacturing costs [10] Group 5: Performance Evaluation of Zippy - Zippy's performance was rigorously tested for walking speed, turning ability, and terrain adaptability, demonstrating excellent energy efficiency and stability on uneven surfaces [5][25] - The robot successfully navigated obstacles, including 2 mm and 3 mm steps, and maintained an average speed of 16.7 cm/s on random terrain [23] Group 6: Future Prospects - Zippy's development opens new avenues for small robot design, proving that miniaturizing passive dynamic walking principles can create compact and flexible robots with stable movement capabilities [26] - Future improvements include integrating an inertial measurement unit (IMU) for real-time gait adjustments and visual navigation capabilities, enabling multiple Zippy robots to work collaboratively in narrow or hazardous environments [27]