KorevaarLab
Research
These movies (↑) feature an example of our research: We have developed self-assembling structures that organize themselves into wires and networks at the millimeter length scale – in a (primitive) analogy to the growth of slime molds in nature. Our system combines the self-assembly of a linear amphiphile into wires 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. Furthermore, we are working on strategies by which these molecular signals 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 filaments that in analogy to neurons establish dynamic connections in self-organizing neuromorphic circuits.
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.
Recent highlights of our work include:
Our paper in Nature Communications about the self-organization of our amphiphile filaments and droplets. Or check out this article by NEMO Kennislink (in Dutch).
We show how the trajectory of the myelins can be directed towards selected photo-active droplets upon localized UV exposure. Furthermore, we establish re-configurability of the connections amongst various droplets, and we demonstrate a photo-controlled transport of fluorescent dyes by the myelins – as an example of chemical communication through the self-assembled connections. (link)
Drain droplets that spontaneously orbit around the source droplet. (link)
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)
A perspective article on “Spatial programming of self-organizing chemical systems using sustained physicochemical gradients from reaction, diffusion and hydrodynamics”. (link)
We established the concept of quorum sensing – known to orchestrate collective behavior in unicellular organisms – in emulsion droplet systems. Initial repulsion between droplets upon surfactant release is counteracted when the droplets release sufficient surfactant precursor that suppresses the repulsive surface tension gradients, providing droplet clustering selectively above a critical droplet density. (link)
We use our myelin assemblies as dynamic pathways to guide the growth of electrodeposited copper dendrites. To this end, we discovered a unique interaction between myelin assemblies that deliver copper(II) ions to the tips of copper dendrites, which in turn grow along the Cu2+ gradient upon electrodeposition. We envision that this approach provides novel strategies for controlled growth of solid wires along directed gradients, and ultimately opens pathways for reconfigurable connections in adaptive networks. (link)