Graphene-based bimorphs for micron-sized, autonomous origami machines

Area of Science:

• Materials Science
• Mechanical Engineering
• Nanotechnology

Background:

• Origami-inspired fabrication offers a path to miniaturized machines.
• Maintaining material properties like conductivity and flexibility during folding is crucial for device function.
• Achieving extreme miniaturization requires novel materials and fabrication techniques.

Purpose of the Study:

• To explore the limits of origami fabrication using two-dimensional (2D) atomic membranes.
• To develop ultrathin, functional actuators for micro-scale machines.
• To demonstrate the creation of responsive micro-robots using origami principles.

Main Methods:

• Utilizing graphene sheets bonded to nanometer-thick glass layers to create ultrathin bimorph actuators.
• Inducing bending in actuators through small strain differentials, well below the fracture threshold.
• Patterning rigid panels on bimorphs to localize bending and create folds for origami structures.
• Integrating electronic, photonic, and chemical payloads for advanced functionality.

Main Results:

• Successfully fabricated ultrathin bimorph actuators capable of bending to micrometer radii of curvature.
• Demonstrated that the actuators maintain conductivity under strain.
• Showcased actuators lifting panels equivalent to a 500-nm-thick silicon chip.
• Developed micro-machines that change shape rapidly in response to tunable pH thresholds.

Conclusions:

• Origami fabrication using 2D atomic membranes represents an ultimate limit in miniaturization.
• The developed graphene bimorphs enable the creation of functional micro-robots with sensing and response capabilities.
• This platform holds significant potential for developing micro-scale robotics with integrated payloads.