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Confinement is essential to trigger this effect, known as thermo-osmosis, leading to a non-vanishing off-diagonal Onsager coefficient coupling mass flow and temperature gradients. Linear response theory allows us to explain this phenomenon from a microscopic standpoint. Specializing such an approach to a simple model, where the fluid is confined in a closed slab by frictionless walls, a solution respecting the symmetries of the system can be found. Enforcing conservation laws, several quantitative predictions have been obtained. In this study, we investigate, by nonequilibrium molecular dynamics simulations, the scaling of this solution with the width of the channel, showing that the analytical expressions reproduce very accurately both the pressure gradient and the velocity profiles observed in simulations in narrow channels. By increasing the pore width, non-linear effects in the energy transport must be taken into account, leading to a breakdown of linear response theory. However, for physically achievable thermal gradients, the analytical solution is shown to be consistent up to the mesoscopic regime.<\/jats:p>","DOI":"10.1063\/5.0288358","type":"journal-article","created":{"date-parts":[[2026,2,11]],"date-time":"2026-02-11T12:27:14Z","timestamp":1770812834000},"update-policy":"https:\/\/doi.org\/10.1063\/aip-crossmark-policy-page","source":"Crossref","is-referenced-by-count":0,"title":["Thermo-osmotic flows in closed channels"],"prefix":"10.1063","volume":"164","author":[{"ORCID":"https:\/\/orcid.org\/0009-0006-8796-0996","authenticated-orcid":false,"given":"Matteo","family":"Bessega","sequence":"first","affiliation":[{"name":"Dipartimento di Scienza e Alta Tecnologia, Universit\u00e0 degli Studi dell\u2019Insubria 1 , Via Valleggio 11, 22100 Como,","place":["Italy"]},{"name":"To.Sca.Lab, Universit\u00e0 degli Studi dell\u2019Insubria 2 , Via Valleggio 11, 22100 Como,","place":["Italy"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9065-9236","authenticated-orcid":false,"given":"Pietro","family":"Anzini","sequence":"additional","affiliation":[{"name":"Dipartimento di Scienza e Alta Tecnologia, Universit\u00e0 degli Studi dell\u2019Insubria 1 , Via Valleggio 11, 22100 Como,","place":["Italy"]},{"name":"To.Sca.Lab, Universit\u00e0 degli Studi dell\u2019Insubria 2 , Via Valleggio 11, 22100 Como,","place":["Italy"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7844-6916","authenticated-orcid":false,"given":"Alberto","family":"Parola","sequence":"additional","affiliation":[{"name":"Dipartimento di Scienza e Alta Tecnologia, Universit\u00e0 degli Studi dell\u2019Insubria 1 , Via Valleggio 11, 22100 Como,","place":["Italy"]},{"name":"To.Sca.Lab, Universit\u00e0 degli Studi dell\u2019Insubria 2 , Via Valleggio 11, 22100 Como,","place":["Italy"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"317","published-online":{"date-parts":[[2026,2,11]]},"reference":[{"key":"2026021107270846100_c1","doi-asserted-by":"publisher","first-page":"57","DOI":"10.1007\/s10404-014-1405-z","article-title":"Capillary filling speed of ferrofluid in hydrophilic microscope slide nanochannels","volume":"18","year":"2015","journal-title":"Microfluid. 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