Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance work on Wednesday 22nd May 2019 from 11:00 AM to 1:00 PM (GMT).

During this time our website performance may be temporarily affected. We apologise for any inconvenience this might cause and thank you for your patience.

Issue 47, 2018
Previous Article Next Article

Diffusiophoretic design of self-spinning microgears from colloidal microswimmers

Author affiliations


The development of strategies to assemble microscopic machines from dissipative building blocks are essential on the route to novel active materials. We recently demonstrated the hierarchical self-assembly of phoretic microswimmers into self-spinning microgears and their synchronization by diffusiophoretic interactions [Aubret et al., Nat. Phys., 2018]. In this paper, we adopt a pedagogical approach and expose our strategy to control self-assembly and build machines using phoretic phenomena. We notably introduce Highly Inclined Laminated Optical sheets microscopy (HILO) to image and characterize anisotropic and dynamic diffusiophoretic interactions, which cannot be performed by conventional fluorescence microscopy. The dynamics of a (haematite) photocatalytic material immersed in (hydrogen peroxide) fuel under various illumination patterns is first described and quantitatively rationalized by a model of diffusiophoresis, the migration of a colloidal particle in a concentration gradient. It is further exploited to design phototactic microswimmers that direct towards the high intensity of light, as a result of the reorientation of the haematite in a light gradient. We finally show the assembly of self-spinning microgears from colloidal microswimmers and carefully characterize the interactions using HILO techniques. The results are compared with analytical and numerical predictions and agree quantitatively, stressing the important role played by concentration gradients induced by chemical activity to control and design interactions. Because the approach described hereby is generic, this works paves the way for the rational design of machines by controlling phoretic phenomena.

Graphical abstract: Diffusiophoretic design of self-spinning microgears from colloidal microswimmers

Back to tab navigation

Supplementary files

Publication details

The article was received on 28 Aug 2018, accepted on 09 Nov 2018 and first published on 13 Nov 2018

Article type: Paper
DOI: 10.1039/C8SM01760C
Soft Matter, 2018,14, 9577-9588

  •   Request permissions

    Diffusiophoretic design of self-spinning microgears from colloidal microswimmers

    A. Aubret and J. Palacci, Soft Matter, 2018, 14, 9577
    DOI: 10.1039/C8SM01760C

Search articles by author