Reprogrammable Dual-Regulated Pollen Actuators for Geometric Encoding

Area of Science:

• Materials Science
• Biomaterials Engineering
• Responsive Systems

Background:

• Bilayer actuators are crucial for intelligent systems but face challenges in scalable, sustainable programming and reprogramming.
• Existing actuators struggle with simultaneous control over both active and passive layers for complex shape transformations.

Purpose of the Study:

• To develop a novel bilayer actuator with dual-layer re-programmability using sustainable biomaterials.
• To demonstrate complex 3D shape transformations and data encryption capabilities.

Main Methods:

• Fabrication of a bilayer actuator using digitally patterned toner (passive layer) and pollen (active layer).
• Tuning humidity responsiveness of the pollen layer via pH.
• Utilizing a mild alkaline process for disassembly and reprogramming.

Main Results:

• The passive layer dictates deformation direction (0° to ≈152° folding angles).
• The active pollen layer shows tunable humidity responsiveness (0.036 to 0.28 cm⁻¹ curvature, 1.04 to 0.15° s⁻¹ response speed).
• The actuator system achieved over 10 reprogramming cycles without degradation and demonstrated data encryption.

Conclusions:

• A novel, eco-friendly bilayer actuator platform based on pollen offers unprecedented dual-layer re-programmability.
• The system supports complex 3D transformations and encrypted data storage, paving the way for next-generation responsive materials and smart devices.