Reprogrammable Dual-Regulated Pollen Actuators for Geometric Encoding.

Abstract

Bilayer actuators capable of autonomously responding to complex environmental stimuli have attracted increasing interest for their potential in intelligent and multifunctional systems. Yet, achieving simultaneous programming and reprogramming of shape transformations in both active and passive layers through scalable, sustainable methods remains a significant challenge. Here, a novel bilayer actuator derived from naturally abundant pollen is reported, offering unprecedented dual-layer re-programmability. The passive layer, composed of digitally patterned toner, dictates the deformation direction, with the folding angles ranging from 0° to ≈152°. Meanwhile, the active pollen layer exhibits tunable humidity responsiveness modulated by pH, controlling actuation curvature ranging from 0.036 to 0.28 cm cm^-1 and response speed ranging from 1.04 to 0.15° s^-1. Notably, the entire bilayer system can be fully disassembled via a mild, one-pot alkaline process, enabling more than 10 cycles of complete reprogramming without structural degradation. This dual-regulated architecture supports complex 3D geometric transformations and is demonstrated as a carrier of confidential information, encoding data through morphing analogs of encrypted binary code. By integrating programmable mechanics, renewable biomaterials, and energy-efficient reusability, this work establishes an eco-friendly and versatile platform for next-generation responsive materials and encrypted smart devices.