Temperature effects on disk-like gold-nickel-platinum nanoswimmer's propulsion fuelled by hydrogen peroxide

Self-propelled nanoswimmers are designed in a disk shape, consisting of tri-metallic segments: gold (Au), nickel (Ni), and platinum (Pt). A bubble propulsion mechanism originated from momentum change of a Au-Ni-Pt nanoswimmer-oxygen (O₂) bubble integral system is proposed. This innovative type of Au-Ni-Pt segmented nanoswimmers is fabricated using a layer-by-layer deposition method based on nano-electro-mechanical systems (NEMS) technology, whereby Pt functions as the chemical catalyst for the decomposition of hydrogen peroxide (H₂O₂) to produce O₂ bubbles detaching from its surface and water (H₂O), which in turn generates a recoil force to thrust the nanoswimmers propelling forward. Two different sized nanoswimmers’ motion is characterized by changing the temperature of H₂O₂ solution, revealing that O₂ bubbles are generated and detached from the surface of Pt, and the nanoswimmers can autonomously propel forward in either a linear or a circular way. Results show the big nanoswimmer propels forward faster than the small one at temperature below 27 °C, while the small nanoswimmer moves forward faster at temperature above 27 °C. In general, the speed of nanoswimmers is increased with the increment of the temperature of H₂O₂ solution, thus the propulsion of the nanoswimmers is temperature-dependent.