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  • Letter
  • Open Access

Lifting active matter into three dimensions using buoyancy control and external alignment

Sandeep Ramteke1, Jordan Dehmel2, Touvia Miloh3, Jarrod Schiffbauer2,4, and Alicia Boymelgreen1,*

  • *Contact author: aboymelg@fiu.edu
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Phys. Rev. Research 8, L032005 – Published 14 July, 2026

DOI: https://doi.org/10.1103/q9x6-wd7r

Abstract

Sedimentation and gyrotaxis from metallic coatings in synthetic active matter confine particles to quasi-two-dimensional, wall-dominated states. To sustain a true three-dimensional distribution, both effects must be mitigated. Here, density matching in a glycerol/deionized water mixture (counteracting sedimentation) is combined with a uniform ac electric field that aligns and propels particles, minimizing gyrotaxis. Measurement of near-wall and bulk mobilities is now possible, revealing frequency-dependent particle-wall interactions consistent with theory. The method can be extended to other active systems to probe confinement effects and nonequilibrium behavior.

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Outline

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Phys. Rev. Research 8, L032005– Published 14 July, 2026
  • Received 1 May 2025
  • Revised 27 February 2026
  • Accepted 25 April 2026
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