# A Biologically Inspired Height-Adjustable Jumping Robot
## 7 Conclusions  
This study proposed a biologically motivated route-adjustable miniature multi-locomotion robot. We designed the bionic mechanism of the gall midge larvae that belongs to soft-bodied jumping animals and the springtail that belongs to hard-bodied jumping animals; we then combined the two bionic mechanisms to obtain a jumping mechanism with superior performance. Compared with existing jumping robots, our robot displayed the following characteristics. First, it had a powerful energy storage capacity that was up to about 2.9 J of energy at a height of about 10 cm, this was capable of endowing the robot with strong load capacity and jumping ability, which was well reflected in the experimental data. Second, it could adjust its locomotion trajectory based on the obstacle's size through a combination of horizontal and vertical motions. Furthermore, it could be automatically righted by gravity after a fall, thus eliminating the need for any additional righting mechanisms.  
Compared with the existing robots, our robot achieved functions of height-adjustable jumping motion, wheeled motion, and self-righting in the smallest possible size. More importantly, our bouncing unit has better energy storage and load capacities in the smaller size.  
In the future, the robot can be equipped with sensors, cameras, and other tools for military monitoring, reconnaissance, and outer space exploration. In practical applications, it can be improved according to actual situations, such as the selection of more elastic components or a more powerful motor.  
Conceptualization: Y.M.; Data collection: Y.M.; Theoretical analysis: Y.M.; Experiments and testing: Y.M.; Writing--original draft: Y.M.; Writing--review and editing: Y.M., Y.W., and D.K. All authors have read and agreed to the published version of the manuscript.  
This research was supported by the University of Science and Technology of China and the Chinese Academy of Sciences.  
Not applicable.  
\begin{table}
\begin{tabular}{l c c c c c c c c} \hline \hline \multirow{2}{*}{**Robot Name**} & **Mass** & **Size** & **Jumping** & **Height Ad-** & **Self-** & **Steering** & **Energy-Storing** & **Reference** \\  & **(g)** & **(cm)** & **Height (cm)** & **justability** & **Righting** & **Steering** & **Component** & **Factor \(\mathbf{\zeta}\)** \\ \hline JumpRoACH [20] & 99 & 12 & 1.5 & Yes & Yes & Yes & \begin{tabular}{c} Torsional spring \\ and latex rubber \\ \end{tabular} & 1.29 \\ \hline MSU Jumper [4] & 23.5 & 6.5 & 87.2 & No & Yes & Yes & \
\begin{tabular}{c} Torsional spring \\ \end{tabular} & 0.31 \\ \hline Steerable miniature jumping robot [22] & 14 & 18 & 62 & No & Yes & Yes &
\begin{tabular}{c} Torsional spring \\ \end{tabular} & 0.057 \\ \hline
25 g running and jumping robot [7] & 25 & 9 & 144 & No & Yes & Yes &
\begin{tabular}{c} Carbon fiber \\ strips \\ \end{tabular} & 0.4 \\ \hline Flea robot [1] & 1.1 & 2 & 64 & Yes & No & No & SMA spring & 0.035 \\ \hline MultiMo-Bat [6] & 115.6 & 35 & 305 & Yes & No & No & Linear spring & 1.11 \\ \hline Salto-IP [23] & 98 & 15 & 100 & No & No & No & Linear spring & 0.49 \\ \hline Tribot [8] & 10 & 5.8 & 14 & Yes & Yes & No & SMA spring & 0.024 \\ \hline
7 g jumping robot [24] & 5.98 & 5 & 76 & No & Yes & No & Torsional spring & 0.09 \\ \hline Proposed robot & 158.6 & 16.2 & 123 & Yes & Yes & Yes &
\begin{tabular}{c} Torsional spring \\ and hyperelastic \\ Nitonal spring \\ \end{tabular} & 1.5 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Performance comparison of jumping robots.