RT Journal Article
SR Electronic
T1 An 88-milligram insect-scale autonomous crawling robot driven by a catalytic artificial muscle
JF Science Robotics
JO Sci. Robotics
FD American Association for the Advancement of Science
SP eaba0015
DO 10.1126/scirobotics.aba0015
VO 5
IS 45
A1 Yang, Xiufeng
A1 Chang, Longlong
A1 Pérez-Arancibia, Néstor O.
YR 2020
UL http://robotics.sciencemag.org/content/5/45/eaba0015.abstract
AB The creation of autonomous subgram microrobots capable of complex behaviors remains a grand challenge in robotics largely due to the lack of microactuators with high work densities and capable of using power sources with specific energies comparable to that of animal fat (38 megajoules per kilogram). Presently, the vast majority of microrobots are driven by electrically powered actuators; consequently, because of the low specific energies of batteries at small scales (below 1.8 megajoules per kilogram), almost all the subgram mobile robots capable of sustained operation remain tethered to external power sources through cables or electromagnetic fields. Here, we present RoBeetle, an 88-milligram insect-sized autonomous crawling robot powered by the catalytic combustion of methanol, a fuel with high specific energy (20 megajoules per kilogram). The design and physical realization of RoBeetle is the result of combining the notion of controllable NiTi-Pt–based catalytic artificial micromuscle with that of integrated millimeter-scale mechanical control mechanism (MCM). Through tethered experiments on several robotic prototypes and system characterization of the thermomechanical properties of their driving artificial muscles, we obtained the design parameters for the MCM that enabled RoBeetle to achieve autonomous crawling. To evaluate the functionality and performance of the robot, we conducted a series of locomotion tests: crawling under two different atmospheric conditions and on surfaces with different levels of roughness, climbing of inclines with different slopes, transportation of payloads, and outdoor locomotion.