{"slug":"2020-robeetle-catalytic-muscle","href":"/entries/2020-robeetle-catalytic-muscle","api":"/api/v1/entries/2020-robeetle-catalytic-muscle","title":"RoBeetle 2020 — 88 mg methanol-catalytic crawling microrobot","type":"device","status":"active","certainty":"measured","claim":"RoBeetle is an insect-scale crawler (empty mass 88 mg) that instantiates methanol catalytic combustion on Pt coupled to a Pt-coated NiTi wire actuator. Contraction drives forelegs and closes the fuel-tank lid. measured [@yang2020robeetle]","mechanism":"1. Energy store: onboard liquid methanol tank (~120 µl class); ambient evaporation feeds vapor through dorsal ports. reported [@yang2020robeetle]\n2. Actuator: NiTi SMA wire diameter 50.8 µm with platinum powder coating as catalyst surface. measured [@yang2020robeetle]\n3. Heat from catalytic combustion drives martensite→austenite contraction (As 87–99 °C). measured [@yang2020robeetle]\n4. Transmission: contraction displaces a leaf spring / linkage to the forelegs and simultaneously closes the tank lid, modulating further vapor delivery. reported [@yang2020robeetle]\n5. Reset: cooling restores wire length via return spring; lid reopens; cycle repeats. reported [@yang2020robeetle]\n6. Locomotion: two-anchor crawl with anisotropic friction. reported [@yang2020robeetle]\n7. Mass budget: empty ≈ 88 mg; fueled ≈ 183 mg; fuel ≈ 95 mg. Length ≈ 20 mm. measured/reported [@yang2020robeetle] [@ieee2020robeetle]\n8. Payload: up to ~2.6× empty mass reported. Stride ~1.2 mm. measured/reported [@yang2020robeetle] [@ieee2020robeetle]\n9. No onboard electronics in the demonstrated crawler; control is thermo-mechanical via the catalytic/SMA coupling. reported [@yang2020robeetle]\n10. This device demonstrates methanol-catalytic-combustion-on-pt; it is not the principle itself.","quantities":[{"name":"empty_mass","unit":"mg","value":"88","source":"yang2020robeetle","certainty":"measured"},{"name":"fueled_mass","unit":"mg","value":"183","source":"yang2020robeetle","certainty":"measured"},{"name":"fuel_mass","unit":"mg","value":"~95","source":"yang2020robeetle","certainty":"measured"},{"name":"length","unit":"mm","value":"~20","source":"ieee2020robeetle","certainty":"reported"},{"name":"niti_wire_diameter","unit":"µm","value":"50.8","source":"yang2020robeetle","certainty":"measured"},{"name":"max_payload","unit":"× empty mass","value":"~2.6","source":"yang2020robeetle","certainty":"measured"},{"name":"stride","unit":"mm","value":"~1.2","source":"ieee2020robeetle","certainty":"reported"},{"name":"tank_volume","unit":"µl","value":"~120","source":"yang2020robeetle","certainty":"reported"}],"limits":"Chemical→work efficiency ~0.48%. Cycle limited by evaporation and catalyst fouling. Methanol toxic. Wire ≈ 90–100 °C. No onboard electronics. Secondary IEEE summary may invert SMA heating clause relative to yang2020robeetle — prefer primary.","inventor_note":"","sources":[{"key":"yang2020robeetle","note":"primary source"},{"key":"ieee2020robeetle","note":"secondary; check SMA clause against primary"},{"key":"usc2020robeetle","note":"institutional note"}],"links":["methanol-catalytic-combustion-on-pt"],"relations":[{"slug":"methanol-catalytic-combustion-on-pt","rel":"demonstrates"}],"topics":[{"id":"micro-robotics","title":"Micro-robotics"}],"created_at":"2026-10-01T19:14:49.242Z","updated_at":"2026-10-01T19:14:49.307Z"}