{"entity": "publication", "iuid": "e51212375cd14eee9c363f341228a4c9", "timestamp": "2026-08-20T21:11:47.814Z", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/e51212375cd14eee9c363f341228a4c9.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/e51212375cd14eee9c363f341228a4c9"}}, "title": "Acoustic focusing of beads and cells in hydrogel droplets.", "authors": [{"family": "Fornell", "given": "Anna", "initials": "A"}, {"family": "Pohlit", "given": "Hannah", "initials": "H"}, {"family": "Shi", "given": "Qian", "initials": "Q"}, {"family": "Tenje", "given": "Maria", "initials": "M"}], "type": "journal article", "published": "2021-04-05", "journal": {"title": "Sci Rep", "issn": "2045-2322", "volume": "11", "issue": "1", "pages": "7479", "issn-l": "2045-2322"}, "abstract": "The generation of hydrogel droplets using droplet microfluidics has emerged as a powerful tool with many applications in biology and medicine. Here, a microfluidic system to control the position of particles (beads or astrocyte cells) in hydrogel droplets using bulk acoustic standing waves is presented. The chip consisted of a droplet generator and a 380 \u00b5m wide acoustic focusing channel. Droplets comprising hydrogel precursor solution (polyethylene glycol tetraacrylate or a combination of polyethylene glycol tetraacrylate and gelatine methacrylate), photoinitiator and particles were generated. The droplets passed along the acoustic focusing channel where a half wavelength acoustic standing wave field was generated, and the particles were focused to the centre line of the droplets (i.e. the pressure nodal line) by the acoustic force. The droplets were cross-linked by exposure to UV-light, freezing the particles in their positions. With the acoustics applied, 89 \u00b1 19% of the particles (polystyrene beads, 10 \u00b5m diameter) were positioned in an area \u00b1 10% from the centre line. As proof-of-principle for biological particles, astrocytes were focused in hydrogel droplets using the same principle. The viability of the astrocytes after 7 days in culture was 72 \u00b1 22% when exposed to the acoustic focusing compared with 70 \u00b1 19% for samples not exposed to the acoustic focusing. This technology provides a platform to control the spatial position of bioparticles in hydrogel droplets, and opens up for the generation of more complex biological hydrogel structures.", "doi": "10.1038/s41598-021-86985-7", "pmid": "33820916", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC8021569"}, {"db": "pii", "key": "10.1038/s41598-021-86985-7"}], "notes": [], "created": "2026-08-20T09:05:24.049Z", "modified": "2026-08-20T09:05:24.096Z"}