Periodic Reporting for period 1 - brightLINK (Light-induced macroscopic assembly under dissipative conditions: communication between artificial swimmers)
Reporting period: 2023-09-01 to 2025-08-31
The project’s objectives are: (1) design and fabricate photo‑responsive soft walkers—miniature structures that bend and walk under controlled light; (2) engineer functional hydrogels that act as a “chemical message bus,” storing and transporting molecules on demand; (3) couple walkers and hydrogels so that motion can trigger, route and time chemical signals across space; and, overall, extract general design rules (materials, geometry, illumination) that others can reuse. During the first phase, we achieved light‑driven walking on surfaces (a walker rather than the initially envisioned swimmer) and established hydrogel thin film platforms for controllable reaction diffusion capabilities.
By turning light into coordinated function at the micro‑ to mesoscale, the project advances soft robotics and responsive materials. Expected impacts include cleaner actuation (light as an external, on‑demand input), programmable communication between devices, and reusable protocols and datasets to accelerate innovation. These outcomes support broader priorities on sustainable, digitised technologies by enabling precise control of materials and processes with low-footprint methods.
Design rules through iteration. We explored families of designs (arrays, legged micro‑elements and flat architectures) and mapped how thickness, pillar density, aspect ratio, and illumination conditions affect actuation and net translation. This work produced practical guidelines for achieving motion while avoiding frictional locking and optical attenuation, which are key barriers for soft, free-form, untethered locomotion.
Hydrogels for chemical messaging. In parallel, we created thin‑layer hydrogel platforms that store and transport molecular “messages.” We established quantitative diffusion assays for model cargos and a simple predictive model linking layer thickness and geometry to release profiles. These tools let us time and route chemical signals with minimal energy input.
Why it matters. This approach offers clean, on‑demand control (light as an external, selective input) and a path to distributed behaviours in lab‑on‑a‑chip, smart surfaces, and targeted release systems. The accompanying design rules (geometry/alignment/illumination; friction management; optical access) lower the barrier for others to reproduce and adapt these capabilities.
What is needed for broader uptake.
- Further research: optimise speed, step size and dynamic directionality; expand symmetry‑breaking strategies for swimming; integrate simple feedback for closed‑loop operation.
- Demonstration: package the walker–hydrogel coupling into application‑oriented demonstrators (e.g. surface‑bound sensors, programmable release).
- Standards & reproducibility: share benchmark geometries, illumination parameters and X‑ray‑based alignment metrics to support cross‑lab comparability and regulatory readiness in bio‑adjacent uses.
- Ecosystem links: engage microfluidics, system chemistry, out-of-equilibrium dynamics, and soft‑robotics communities (and relevant partners) to align with market needs, manufacturability, and materials compliance.
Expected impact. By turning light into coordinated, chemical‑aware function at small scales, the project provides building blocks for safer, lower‑footprint technologies where precise control is required but electronics are impractical.