Project 03 · 2023–2024 · Completed

Enough good swimmers,
not just the best ones.

If RSM proved EVA selects the best sperm, Inno R&D set out to make it select enough of them, without giving up that quality.

Project insight

A third cue, added by design.

Inno R&D combined a third natural cue, thigmotaxis, the tendency of sperm to swim along surfaces and channel walls, with the rheotaxis and thermotaxis already at work in the device.

Two ideas drove the redesign. A "spoon-like" micro-structure at a narrowing (venturi) zone acts as a gate: only cells strong enough to swim counter-flow pass through, filtering out immotile cells by their own behaviour. Fine sub-micro-channels alongside the main channels give sperm more guided edges to hug, since the cells naturally follow boundaries, channelling more of the good swimmers toward the collection point and raising the recovered concentration.

Venturi gate Sub-micro-channels
A venturi-zone gate lets only strong counter-flow swimmers through, while sub-micro-channels give sperm more surfaces to follow, thigmotaxis, on the way to the collection point.
Innovation

Simulated first, fabricated once.

Rather than fabricate every variant by hand, the team validated the concepts computationally, importing the 3D designs into a finite-element / CFD framework (COMSOL) and coupling laminar-flow and heat-transfer physics to model the velocity, pressure, and temperature fields inside each geometry.

  • Channel geometry and spacing were explored systematically and refined to concentrate the effect, without needing a single physical prototype for each variant.
  • The result was an optimised device design engineered to lift throughput while preserving the near-perfect quality EVA had already demonstrated in RSM.
  • The work was carried out in Beezbiotech's own micro-fabrication laboratory at the Biopôle in Rennes.
iProject info
Period
2023–2024
Programme
Région Bretagne
Method
CFD simulation (COMSOL)
Keywords
Thigmotaxis, venturi gate, sub-micro-channels, laminar flow
RheotaxisThermotaxisThigmotaxis
APAnais PeyronEx-Business Engineer Dr. Shiva Kant ShuklaDr. Shiva Kant ShuklaPrincipal Investigator
Dissemination

Funded by Région Bretagne.

Carried out entirely in-house, in Beezbiotech's own micro-fabrication laboratory at the Biopôle in Rennes.

Région Bretagne

Innov-R&D grant that funded this stage of EVA's device optimisation.

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