Abstract
Chemotactic interactions are ubiquitous in nature and can lead to non-reciprocal and complex emergent behaviour in multibody systems. However, developing synthetic, inanimate embodiments of a chemomechanical framework to generate non-reciprocal interactions of tunable strength and directionality has been challenging. Here we show how chemotactic signalling between microscale oil droplets of different chemistries in micellar surfactant solutions can result in predator–prey-like non-reciprocal chasing interactions. The interactions and dynamic self-organization result from the net directional, micelle-mediated transport of oil between emulsion droplets of differing composition and are powered by the free energy of mixing. We systematically elucidated chemical design rules to tune the interactions between droplets by varying the oil and surfactant chemical structure and concentration. Through the integration of experiment and simulation, we also investigated the active behaviour and dynamic reorganization of multidroplet clusters. Our findings demonstrate how chemically minimal systems can be designed with controllable, non-reciprocal chemotactic interactions to generate emergent self-organization and collective behaviours reminiscent of biological systems. [Figure not available: see fulltext.]
| Original language | English |
|---|---|
| Pages (from-to) | 1136-1142 |
| Number of pages | 7 |
| Journal | Nature Chemistry |
| Volume | 12 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - 1 Dec 2020 |
Funding
We thank C. Wentworth for her help obtaining interfacial tension measurements using the pendant drop method. L.D.Z., C.H.M. and Y.-J.C. acknowledge support from the Army Research Office through grant no. W911NF-18-1-0414 and the Penn State MRSEC funded by the National Science Foundation (DMR-1420620). C.H.M. acknowledges support from the Thomas and June Beaver Fellowship at Penn State and the Pennsylvania Space Grant Fellowship, and Y.-J.C. received support from the Erickson Discovery Grant Program at Penn State. P.G.M. acknowledges funding from the NWO (Dutch National Science Foundation) Graduate Program through the Debye Institute for Nanomaterials. J.G. wishes to thank the program for Chang Jiang Scholars and Innovative Research Teams in Universities (no. IRT 17R40) and the 111 Project of the PRC.