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However, replicating these motions in artificial systems remains challenging given the\u00a0limits of scalable, locally controllable soft-bodied actuation at the micrometre scale. Overcoming this challenge would enhance our understanding of ciliary dynamics, clarify their biological importance and enable new microscale devices and bioinspired technologies. Here we show a previously unrecognized fast electrical response of micrometre-scale hydrogels, induced by voltages down to 1.5\u2009V without hydrolysis, with bending motions driven by ion migration across a nanometre-scale hydrogel network 3D-printed by two-photon polymerization, occurring within milliseconds. On the basis of these findings, we print gel microcilia arrays composed of a\u00a0soft acrylic acid-co-acrylamide (AAc-co-AAm) hydrogel (modulus of\u00a0approximately 1,000\u2009Pa) that respond to electrical stimuli within milliseconds. Each microcilium measures 2\u201310\u2009\u00b5m in diameter and 18\u201390\u2009\u00b5m in height, achieving 3D rotational bending motion at up to 40\u2009Hz, mirroring the geometry and dynamics of natural cilia. These gel microcilia maintain functionality after 330,000 continuous actuation cycles with less than 30% performance degradation. The gel microcilia arrays can be integrated on flexible polyimide substrates and fabricated at large scale using conventional lithography techniques. They also offer individual dynamic control by means of microelectrode arrays and enable fluid manipulation and particle transport at the micrometre scale.\n                  <\/jats:p>","DOI":"10.1038\/s41586-025-09944-6","type":"journal-article","created":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T16:01:25Z","timestamp":1768406485000},"page":"885-893","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":30,"title":["3D-printed low-voltage-driven ciliary hydrogel microactuators"],"prefix":"10.1038","volume":"649","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9211-6603","authenticated-orcid":false,"given":"Zemin","family":"Liu","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5382-7106","authenticated-orcid":false,"given":"Che","family":"Wang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ziyu","family":"Ren","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6130-3553","authenticated-orcid":false,"given":"Chunxiang","family":"Wang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wenkang","family":"Wang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jongkuk","family":"Ko","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7225-2552","authenticated-orcid":false,"given":"Shanyuan","family":"Song","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0739-7552","authenticated-orcid":false,"given":"Chong","family":"Hong","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xi","family":"Chen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8552-2323","authenticated-orcid":false,"given":"Hongguang","family":"Wang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3457-821X","authenticated-orcid":false,"given":"Wenqi","family":"Hu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8249-3854","authenticated-orcid":false,"given":"Metin","family":"Sitti","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,1,14]]},"reference":[{"key":"9944_CR1","doi-asserted-by":"publisher","first-page":"056601","DOI":"10.1088\/0034-4885\/78\/5\/056601","volume":"78","author":"J Elgeti","year":"2015","unstructured":"Elgeti, J., Winkler, R. 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