Evidence map›Paper›PMID 42884950›Full record

ArticlePolymers2026

Additive Manufacturing of Thermochromic Chitosan Hydrogels for Battery-Free Colorimetric Thermal Indication.

Jaewon Lim, Na Kyoung Kim, Jong Woo Hah, Yoo Sei Park, Inhwan Lee, Hyoryung Nam, Geon Hwee Kim

Abstract read
In one paragraph

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

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Jaewon LimDepartment of Mechanical Engineering, Chungbuk National University (CBNU), 1, Chungdae-ro, Seowon-gu, Cheongju 28644, Republic of Korea.
Na Kyoung KimDepartment of Mechanical Engineering, Chungbuk National University (CBNU), 1, Chungdae-ro, Seowon-gu, Cheongju 28644, Republic of Korea.
Jong Woo HahDepartment of Mechanical Engineering, Chungbuk National University (CBNU), 1, Chungdae-ro, Seowon-gu, Cheongju 28644, Republic of Korea.
Yoo Sei ParkDepartment of Nanoenergy Engineering, Pusan National University, Busandaehak-ro 63 Beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea.ORCID 0000-0002-5154-2323
Inhwan LeeDepartment of Mechanical Engineering, Chungbuk National University (CBNU), 1, Chungdae-ro, Seowon-gu, Cheongju 28644, Republic of Korea.ORCID 0000-0001-9381-4908
Hyoryung NamDepartment of Biomedical Engineering, Daegu Catholic University School of Medicine, 33 Duryugongwon-ro 17-gil, Nam-gu, Daegu 42472, Republic of Korea.ORCID 0000-0003-3151-8585
Geon Hwee KimDepartment of Mechanical Engineering, Chungbuk National University (CBNU), 1, Chungdae-ro, Seowon-gu, Cheongju 28644, Republic of Korea.ORCID 0000-0003-3178-4947

Funding

Chungbuk National UniversityChungcheongbuk-do 2026-RISE-11-014-03Ministry of Education 2026-RISE-11-014-03National Research Foundation of Korea RS-2026-25479266
6 · The paper itself

Abstract

Battery-free, at-a-glance thermal readouts are attractive for point-of-care triage and low-resource settings. However, three-dimensional thermochromic hydrogel printing remains challenging because delayed gelation can compromise linewidth control and multilayer structural fidelity. In this study, a syringe-pump-driven extrusion-based direct ink writing platform was integrated with a temperature-controlled coagulation bath to induce immediate in situ gelation during thermochromic chitosan hydrogel printing. Systematic tuning of the nozzle gauge, printing speed, and flow rate, combined with rapid thermal gelation in the heated coagulation bath, mitigated die swelling, with the die-swelling ratio, which ranged from 2.1 to 3.7 at low printing speed, decreasing to approximately 1.0 at intermediate speeds. This enabled parameter-dependent control of strand diameter and reproducible multilayer fabrication. The mechanical properties of the printed hydrogels were further tuned by varying the coagulation bath temperature and chitosan concentration; gelation at 60 °C yielded the highest ultimate tensile strength (0.172 MPa), and a 4.0 wt% chitosan formulation provided the most balanced combination of strength and extensibility. Adjusting the thermochromic pigment composition modulated chromatic separation across temperature states in CIE L*a*b* color space over 26-54 °C. Formulation tuning broadened the separation of color states within an intermediate range of 31-38 °C, which spans normal skin temperature and the febrile range relevant to fever detection. The colorimetric response remained stable over 50 heating-cooling cycles, with color differences below the threshold of visual perceptibility. A multilayer construct further demonstrated layer-resolved colorimetric readout within a single 3D structure, indicating the potential of this passive hydrogel indicator for battery-free, spatially resolved thermal indication in this temperature range.

Indexed as

colorimetric thermal indicationdirect ink writingmultilayer hydrogelpassive thermal indicationthermochromic hydrogel

Identifiers

PMID42884950
PMCPMC13666924

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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.