These movies (↑) feature an example of our research: We have developed self-assembling structures that organize themselves into wire-like structures at the millimeter length scale – in a (primitive) analogy to the growth of slime mold wires. Our system combines the self-assembly of a linear amphiphile with surfactant release/depletion dynamics at air-water interfaces that result in sustained Marangoni flows. Whereas the Marangoni flows generate repulsive forces that push the source and drain droplets apart, the filaments that originate from the source tether to the drain droplets, resulting in attractive forces. A controlled balance between these repulsive and attractive forces enables an out-of-equilibrium positioning of complex dynamic assemblies at air-water interfaces.
We aim at molecular information processing through these self-assembling wires that “guide” molecular inputs along adaptive pathways amongst sender and receiver agents. Ultimately, these molecular signals will dictate – via chemical reactions, molecular assembly and (physico)chemical feedback mechanisms – how the network self-organizes to generate functional behavior: Imagine for example self-organizing device interfaces that “determine” the path for a sample in lab-on-a-chip applications, or neuromorphic sensors that analyze complex molecular input and generate optical read-outs that can easily be classified.
We are interested in developing chemistry that introduces life-like behavior in synthetic matter. Synthetic materials as we use them nowadays are typically inactive and limited to just one function. Living materials however follow a completely different approach, and sense what happens in their environment, adapt to changing circumstances and even reorganize themselves to perform multiple tasks. For example, social amoeba cells self-organize into multicellular fruiting bodies, and slime molds grow long wires toward places where food is available.
Interestingly, all this behavior is programmed in the molecular building blocks of life, and the chemistry among them. In our lab, we try to implement this life-like behavior into synthetic materials, such that they perform complex operations in response to their environment – for example motion, growth or shape-transformation. Thereby, we aim to open entirely new possibilities in a next generation of intelligent matter.
Creating life-like matter is a great challenge for the field of Systems Chemistry. In our research, we aim to arrive at self-organizing matter by exploiting phenomena that emerge from unique combinations of self-assembly, chemical reaction networks and surface tension phenomena.
To arrive at patterns, networks and structures that form via self-organization, we are interested in developing control mechanisms which direct such processes, by combining surfactants, self-assembly, chemical reactions and surface tension phenomena (i.e. Marangoni flow).
Recent highlights of our work include:
Filaments that attract selected droplets, based on their chemical content. (link)
Coupling between a set of chemical reactions and the Marangoni effect, leading to an emerging out-of-equilibrium system. We manipulate the surface tension of the air-water interface via photochemistry to create a Marangoni flow that keeps itself ‘alive’ by delivering reagents to the reaction site – enabling new feedback mechanisms to sustain out-of-equilibrium systems. (link)
Drain droplets that spontaneously orbit around the source droplet. (link)
A perspective article on “Spatial programming of self-organizing chemical systems using sustained physicochemical gradients from reaction, diffusion and hydrodynamics”. (link)