Visible-Light-Driven, Nickel-Doped Cobalt Oxides/Hydroxides Actuators with High Stability

Area of Science:

• Materials Science
• Nanotechnology
• Robotics

Background:

• Light-driven actuators are crucial for untethered, miniaturized devices and microrobots.
• Nickel hydroxide/oxyhydroxide and cobalt oxides/hydroxides are promising due to their actuation response and low fabrication cost.
• Actuation in these materials relies on water desorption from turbostratic structures, leading to performance degradation over time due to crystallization.

Purpose of the Study:

• To develop a more stable light-driven actuator for miniaturized devices.
• To investigate nickel-doped cobalt oxides/hydroxides (NiCoO(OH)) as an improved actuator material.
• To understand the role of structural stability in light-driven actuation.

Main Methods:

• Fabrication of nickel-doped cobalt oxides/hydroxides (NiCoO(OH)) via electrodeposition.
• Characterization of the crystal structure and actuation properties of NiCoO(OH).
• Comparative analysis of NiCoO(OH) stability against cobalt oxides/hydroxides (CoO(OH)) and nickel hydroxide/oxyhydroxide (Ni(OH)2/NiOOH).

Main Results:

• NiCoO(OH) exhibits turbostratic crystal structures and actuation magnitude comparable to CoO(OH).
• NiCoO(OH) demonstrates significantly slower crystallization, leading to more stable actuation than CoO(OH) or Ni(OH)2/NiOOH.
• The new actuator shows enhanced applicability compared to its non-doped counterparts.

Conclusions:

• A stabilized turbostratic structure is key for high light-driven actuation in transition-metal oxide/hydroxide actuators.
• Nickel-doped cobalt oxides/hydroxides offer a promising solution for stable, long-lasting light-driven actuators.
• This research advances the development of reliable microrobotic and miniaturized devices.