From light fueled self-oscillators to light communicating material networks

Project Information

ONLINE

Grant agreement ID: 101076207

DOI

10.3030/101076207

EC signature date 16 February 2023

Start date 1 March 2023

End date 29 February 2028

Funded under

• European Research Council (ERC)

Total cost

€ 1 495 500,00

EU contribution

€ 1 495 500,00

Coordinated by

TAMPEREEN KORKEAKOULUSAATIO SR
Finland

Periodic Reporting for period 1 - ONLINE (From light fueled self-oscillators to light communicating material networks)

Reporting period: 2023-03-01 to 2025-08-31

Summary of the context and overall objectives of the project

The state-of-the-art.
Life-like materials. There is a trend to devise bioinspired materials that go beyond the static functions (wettability, adhesion control, toughness, etc.) to increasing level of life-like dynamism in material properties. Biological organisms have perfected the reception of multiple landscapes of signals, which are continuously processed to develop diverse and adaptive response to environmental changes. In synthetic systems, responsive materials can now deform under multiple stimuli (e.g. temperature, light, humidity, electric field, pH, chemicals), sometimes even with programmable logics, reconfigurability and training (learning/forgetting) concepts. Although the lines of research above have captured in-depth several sophisticated life-like concepts, they all lack one key aspect of their natural counterparts – communication.

ONLINE aims to develop new concepts of communication between inanimate materials.
What is meant by communication? In biological context, communication refers to interactive behaviour of one organism affecting the current or future behaviour of another. In the context of bioinspired materials, ONLINE will develop life-like material structures that communicate with each other via physical contact, fluidic medium, or optical beams. These inanimate materials will be coupled to form networks that communicate autonomously through light.

How to make them? The core concept behind the communicative materials is self-oscillatory (self-sustained) motions in light-responsive liquid crystal elastomers (LCEs). We have recently discovered that (I) an individual LCE self-oscillator can react to disturbances spontaneously, indicating the ability to interact with surrounding environment; (II) The coupling between individual oscillators can be attained through multiple laser beams, which enables material communication – if one oscillator is disturbed, the whole network percepts. The project goal is to scale down these proof-of-principle concepts to the micro-scale via 2-photon polymerization laser lithography and realize soft material robots that can communicate.

Why is this important? There exists an increasing need for artificial materials that can interact, alike biological systems. However, all the dynamic features of state-of-the-art responsive materials are based on internal material properties, and making individual materials interact with each other is a huge challenge. ONLINE proposes three new model systems for material communication: (I) Microscopic walker swarm, in which the locomotion and patterns of interactions between individuals can be fully programmed; (II) Cilia array that move cooperatively and self-regulate the fluidics at low Reynolds numbers; (III) Homeostasis-like light-communicating coupled network that provides a full set of tunable parameters to mimic the complexity of biological oscillators.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The project is structured into three Work Packages (WPs): materials, oscillators, and microfabrication. Scientific advancements in each WP are synergistically integrated to achieve three primary project objectives: walker swarm, cilia array, and network formation. The project comprises 11 intermediate goals (Gs).
All activities have been actively pursued.
By October 2025, the main achievements are
1. Achieved excellent control over the performance of liquid crystal elastomer (LCE) actuators, including material optimization—such as reducing the phase transition temperature from 90 °C to 40 °C, sharpen the phase transition range, and enhance the material elasticity.
2. Designed a variety of self-oscillator networks, including systems with positive feedback-induced memory, cascading networks, sauna-inspired oscillations, chaotic behavior, and frequency-tunable network loops.
3. Successful implementation of two-photon laser writing system (UpNano) for all kind of micro fabrication, including passive structures and active LCE with bending, contracting, and twisting modes.
4. Developed a side-incidence-based fiber-tip gripper.
5. Development of three models for self-sustained walking, i.e. torus, spiral and incher. The former two show interactive behavior.
6. Development of artificial cilia that performs tunable stroke under water.
7. General study of feedback mechanism and diversify the material network.
8. A self-oscillator can show different behavior once an external force is applied on.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

1. Z. Deng, K. Li, A. Priimagi, H. Zeng*, Light-steerable locomotion using zero-energy modes, Nat. Mater. 2024, 2024, 23, 1728.

Groundbreaking: In 1976, in Purcell’s seminal lecture note about swimming in low Reynolds number, he envisaged an imaginary toroidal structure for enhanced swimming efficiency, as shown in the Figure on the right. Nearly 50 years have passed, but such low-Reynolds-number swimmer has not yet been demonstrated in synthetic systems, or found in nature. This paper reports the first achievement of toroidal swimmer in Stokes regime, the imaginary swimmer proposed by Purcell 50 years ago.

2. H. Guo, K. Li*, J. Yang, D. Li, F. Liu, H. Zeng*, Light-mediated communication in responsive materials ranging from individual self-oscillators to feedback-driven network (accept in Nature Communications)
Groundbreaking: First demonstration of light communication between non-equilibrium material pieces. This article presents the key concept of the project.

3. J. Yang, H. Pi, Z. Deng, H. Guo, W. Shou, H. Zhang, H. Zeng*, Feedback Regulated Opto-Mechanical Soft Robotic Actuators. Cell Reports Physical Science, 2025, 6, 102686.
It offers a general design guideline for attaining optical feedback in photomechanically responsive materials.

ONLINE project overview. Material communication concept (left) and implementation plan (right).