Evidence map›Paper›PMID 42115605›Full record

ArticleMicrosystems & nanoengineering2026

Length-based separation of Arthrospira (Spirulina) platensis trichomes via the self-alignment effect of helical filaments in a straight microchannel.

Kodai Hara, Akihiro Isozaki

Abstract read
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Article in Microsystems & nanoengineering, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

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0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

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5 · Who and what money

Authors and funding

2 authors.

Kodai HaraDepartment of Mechanical Engineering, Ritsumeikan University, Kusatsu, Shiga, Japan.
Akihiro IsozakiDepartment of Mechanical Engineering, Ritsumeikan University, Kusatsu, Shiga, Japan. aisozaki@fc.ritsumei.ac.jp.ORCID http://orcid.org/0000-0003-0391-9832

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Shape-based separation of biological particles has elucidated cellular morphology and function. However, length-based sorting of helical-shaped microorganisms, such as Arthrospira (Spirulina) platensis, in microfluidic platforms has not yet been achieved. Here, we report a passive, length-based sorting method for A. platensis trichomes using a straight microchannel that exploits a self-alignment effect of helical filaments. In our design, trichomes flowed through a straight microchannel narrower than their average length and entered a downstream expanding channel with five outlets. High-speed camera-based observation revealed that shorter trichomes predominantly aligned near the channel walls, whereas longer trichomes spanned the channel width. These alignment tendencies, termed the self-alignment effect, were flow-rate dependent and most prominent at a Reynolds number of 40. Thus, short and long trichomes were guided to different outlet positions. Quantitative analysis showed that at a threshold length of 300 µm, sorting purities of 77% and 84% were achieved for short and long trichomes, respectively. This demonstrates effective, label-free separation of multicellular cyanobacterial filaments based on length in a simple microfluidic geometry. As trichome length reflects the growth stage and environmental response, this method offers a promising platform for studying physiological heterogeneity in A. platensis populations. Furthermore, it can facilitate applications in biotechnology and materials science, where precise selection of filamentous morphologies is desired. This principle can also be applied to other microorganisms or flexible helical structures. The observed self-alignment effect may become a new paradigm in passive microscale sorting.

Identifiers

PMID42115605
PMCPMC13161404

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.