--- _id: '9053' abstract: - lang: eng text: 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. article_processing_charge: No article_type: original author: - first_name: Antoine full_name: Aubret, Antoine last_name: Aubret - first_name: Jérémie A full_name: Palacci, Jérémie A id: 8fb92548-2b22-11eb-b7c1-a3f0d08d7c7d last_name: Palacci orcid: 0000-0002-7253-9465 citation: ama: Aubret A, Palacci JA. Diffusiophoretic design of self-spinning microgears from colloidal microswimmers. Soft Matter. 2018;14(47):9577-9588. doi:10.1039/c8sm01760c apa: Aubret, A., & Palacci, J. A. (2018). Diffusiophoretic design of self-spinning microgears from colloidal microswimmers. Soft Matter. Royal Society of Chemistry . https://doi.org/10.1039/c8sm01760c chicago: Aubret, Antoine, and Jérémie A Palacci. “Diffusiophoretic Design of Self-Spinning Microgears from Colloidal Microswimmers.” Soft Matter. Royal Society of Chemistry , 2018. https://doi.org/10.1039/c8sm01760c. ieee: A. Aubret and J. A. Palacci, “Diffusiophoretic design of self-spinning microgears from colloidal microswimmers,” Soft Matter, vol. 14, no. 47. Royal Society of Chemistry , pp. 9577–9588, 2018. ista: Aubret A, Palacci JA. 2018. Diffusiophoretic design of self-spinning microgears from colloidal microswimmers. Soft Matter. 14(47), 9577–9588. mla: Aubret, Antoine, and Jérémie A. Palacci. “Diffusiophoretic Design of Self-Spinning Microgears from Colloidal Microswimmers.” Soft Matter, vol. 14, no. 47, Royal Society of Chemistry , 2018, pp. 9577–88, doi:10.1039/c8sm01760c. short: A. Aubret, J.A. Palacci, Soft Matter 14 (2018) 9577–9588. date_created: 2021-02-01T13:44:41Z date_published: 2018-12-21T00:00:00Z date_updated: 2023-02-23T13:47:43Z day: '21' doi: 10.1039/c8sm01760c extern: '1' external_id: arxiv: - '1909.11121' pmid: - '30456407' intvolume: ' 14' issue: '47' keyword: - General Chemistry - Condensed Matter Physics language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1909.11121 month: '12' oa: 1 oa_version: Preprint page: 9577-9588 pmid: 1 publication: Soft Matter publication_identifier: eissn: - 1744-6848 issn: - 1744-683X publication_status: published publisher: 'Royal Society of Chemistry ' quality_controlled: '1' scopus_import: '1' status: public title: Diffusiophoretic design of self-spinning microgears from colloidal microswimmers type: journal_article user_id: D865714E-FA4E-11E9-B85B-F5C5E5697425 volume: 14 year: '2018' ...