Photonic Devices Out of Equilibrium: Transient Memory, Signal Propagation, and Sensing

Abstract

Soft photonic materials are important for sensors, displays, or energy management and have become switchable under static equilibrium conditions by integration of responsive polymer features. The next step is to equip such materials with the ability for autonomously dynamic and self-regulating behavior, which would advance their functionality and application possibilities to new levels. Here, this study shows the system integration of a nonlinear, biocatalytic pH-feedback system with a pH-responsive block copolymer photonic gel, and demonstrates autonomous transient memories, remotely controlled signal propagation, and sensing. This study utilizes an enzymatic switch to program the lifetime of the reflective state of a photonic gel, and induces propagation of pH-waves extinguishable by illumination with UV-light. The described combination of nonlinear chemistry and responsive photonic gels opens pathways toward out-of-equilibrium photonic devices with active and autonomous behavior useful for sensing, computation, and communication.

Biocatalytic Feedback‐Controlled Non‐Newtonian Fluids

“…The slow, enzymatic, feedback‐driven pH change creates a transient gelation process that can be programmed in time. Later, they further extended this concept to a photonic gel, which demonstrates autonomous transient memories, remotely controlled signal propagation, and sensing . With the aid of such a powerful tool, time‐lapse polymerization, self‐regulated microgels or supramolecular gels, and self‐adaptive nanoreactors have been successfully demonstrated.…”

Applications of Dissipative Supramolecular Materials with a Tunable Lifetime

“…Moreover, it was also demonstrated that their temporary hydrogels could release hydrophilic dye after a preprogrammed time (Figure d). Because of the generality of the principle, several other assemblies have been formed via this principle including DNA i‐motifs and photonic devices …”

“…Because of the generality of the principle, several other assemblies have been formed via this principle including DNA i-motifs [61] and photonic devices. [62] To demonstrate the use of dissipative materials as delivery vehicles, we recently described the release of hydrophobic dyes from a dissipative supramolecular material. We used Fmocprotected glutamic acid (Fmoc-E, Figure 8a) as a precursor in the carbodiimide-fueled chemical reaction network described in Figure 3a.…”

Dissipative Self‐Assembly of Peptides

“…[13] Moreover, peptides can be chemically modified by conjugation with aromatic groups or aliphatic tails which can further enhance their propensity for self-assembly. In this regard, fluorenyl protected peptides, [14][15][16][17][18] lipopetides [19,20] and peptide amphiphiles [21][22][23][24] have been extensively studied.…”