{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T11:51:32Z","timestamp":1791546692562,"version":"4.3.4"},"reference-count":34,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2024,10,31]],"date-time":"2024-10-31T00:00:00Z","timestamp":1730332800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003052","name":"Ministry of Trade, Industry &amp; Energy (MOTIE, Republic of Korea)","doi-asserted-by":"publisher","award":["P0028061"],"award-info":[{"award-number":["P0028061"]}],"id":[{"id":"10.13039\/501100003052","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003052","name":"Ministry of Trade, Industry &amp; Energy (MOTIE, Republic of Korea)","doi-asserted-by":"publisher","award":["No. 2022002980003"],"award-info":[{"award-number":["No. 2022002980003"]}],"id":[{"id":"10.13039\/501100003052","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003052","name":"Ministry of Trade, Industry &amp; Energy (MOTIE, Republic of Korea)","doi-asserted-by":"publisher","award":["kitech EH240006"],"award-info":[{"award-number":["kitech EH240006"]}],"id":[{"id":"10.13039\/501100003052","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003562","name":"Korea Ministry of Environment (MOE)","doi-asserted-by":"publisher","award":["P0028061"],"award-info":[{"award-number":["P0028061"]}],"id":[{"id":"10.13039\/501100003562","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003562","name":"Korea Ministry of Environment (MOE)","doi-asserted-by":"publisher","award":["No. 2022002980003"],"award-info":[{"award-number":["No. 2022002980003"]}],"id":[{"id":"10.13039\/501100003562","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003562","name":"Korea Ministry of Environment (MOE)","doi-asserted-by":"publisher","award":["kitech EH240006"],"award-info":[{"award-number":["kitech EH240006"]}],"id":[{"id":"10.13039\/501100003562","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003695","name":"Korea Institute of Industrial Technology","doi-asserted-by":"publisher","award":["P0028061"],"award-info":[{"award-number":["P0028061"]}],"id":[{"id":"10.13039\/501100003695","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003695","name":"Korea Institute of Industrial Technology","doi-asserted-by":"publisher","award":["No. 2022002980003"],"award-info":[{"award-number":["No. 2022002980003"]}],"id":[{"id":"10.13039\/501100003695","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003695","name":"Korea Institute of Industrial Technology","doi-asserted-by":"publisher","award":["kitech EH240006"],"award-info":[{"award-number":["kitech EH240006"]}],"id":[{"id":"10.13039\/501100003695","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>This paper presents a simple, fast, and cost-effective method for creating metallic microstructured surfaces by spray-coating a dispersion of copper nanoparticles (CuNPs) onto polymethyl methacrylate (PMMA) substrates, enabling the imbibition-induced wetting of liquid metal. The formation of these microstructured patterns is crucial for the spontaneous wetting of gallium-based liquid metals. Traditional techniques for producing such microstructures often involve complex and costly lithography and vacuum deposition methods. In contrast, this study demonstrates that liquid metal wetting can occur with metal microstructures formed through a straightforward spray-coating process. To immobilize the CuNPs on the polymer substrate, an organic solvent that dissolves the polymer surface was employed as the dispersion medium. The effects of various spray-coating parameters, including distance and time, on the uniformity and immobilization of CuNP films were systematically investigated. Under optimal conditions (120 s of spray time and 10 cm spray distance), CuNPs dispersed in dichloromethane (DCM) yielded uniform and stable microstructured surfaces. The spontaneous wetting of gallium-based liquid metal was observed on the fabricated CuNP film. Additionally, liquid metal selectively wet the CuNP patterns formed by stencil techniques, establishing electrical connections between electrodes. These findings underscore the potential of spray-coating for fabricating metallic surfaces to drive the formation of liquid metal patterns in flexible electronics applications.<\/jats:p>","DOI":"10.3390\/ma17215299","type":"journal-article","created":{"date-parts":[[2024,10,31]],"date-time":"2024-10-31T09:57:36Z","timestamp":1730368656000},"page":"5299","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Facile Formation of Metallic Surface with Microroughness via Spray-Coating of Copper Nanoparticles for Enhanced Liquid Metal Wetting"],"prefix":"10.3390","volume":"17","author":[{"given":"Ji-Hye","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Chemical & Biomolecular Engineering, Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-gu, Seoul 01811, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0720-5714","authenticated-orcid":false,"given":"Ju-Hee","family":"So","sequence":"additional","affiliation":[{"name":"Material & Component Convergence R&D Department, Korea Institute of Industrial Technology, Ansan-si 15588, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6804-741X","authenticated-orcid":false,"given":"Hyung-Jun","family":"Koo","sequence":"additional","affiliation":[{"name":"Department of Chemical & Biomolecular Engineering, Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-gu, Seoul 01811, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,10,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4073","DOI":"10.1039\/C7CS00043J","article-title":"Liquid metals: Fundamentals and applications in chemistry","volume":"47","author":"Daeneke","year":"2018","journal-title":"Chem. Soc. Rev."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2000192","DOI":"10.1002\/advs.202000192","article-title":"Attributes, fabrication, and applications of gallium-based liquid metal particles","volume":"7","author":"Lin","year":"2020","journal-title":"Adv. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"3559","DOI":"10.1002\/adma.201101257","article-title":"Towards all-soft matter circuits: Prototypes of quasi-liquid devices with memristor characteristics","volume":"31","author":"Koo","year":"2011","journal-title":"Adv. Mater."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"625","DOI":"10.1002\/adfm.201101967","article-title":"Ionic current rectification in soft-matter diodes with liquid-metal electrodes","volume":"22","author":"So","year":"2012","journal-title":"Adv. Funct. Mater."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1002","DOI":"10.1038\/s41467-020-14814-y","article-title":"Nanofabrication for all-soft and high-density electronic devices based on liquid metal","volume":"11","author":"Kim","year":"2020","journal-title":"Nat. Commun."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3052","DOI":"10.1007\/s11814-023-1539-3","article-title":"Acoustic performance of flexible polyurethane composite foams filled with melamine particles","volume":"40","author":"Yun","year":"2023","journal-title":"Korean J. Chem. Eng."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1240","DOI":"10.1007\/s11814-023-1394-2","article-title":"Enhancing the electrical conductivity of stretchable silicone composite textiles using ethanol solvent treatment","volume":"40","author":"Kim","year":"2023","journal-title":"Korean J. Chem. Eng."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"101423","DOI":"10.1016\/j.apmt.2022.101423","article-title":"Liquid metal droplets enabled soft robots","volume":"27","author":"Zheng","year":"2022","journal-title":"Appl. Mater. Today"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2309989","DOI":"10.1002\/adfm.202309989","article-title":"Liquid metal functionalization innovations in wearables and soft robotics for smart healthcare applications","volume":"34","author":"Chen","year":"2024","journal-title":"Adv. Funct. Mater."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2200375","DOI":"10.1002\/aisy.202200375","article-title":"Liquid metal smart materials toward soft robotics","volume":"5","author":"Chen","year":"2023","journal-title":"Adv. Intell. Syst."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"38760","DOI":"10.1021\/acsami.8b13257","article-title":"Hydroprinted electronics: Ultrathin stretchable Ag\u2013In\u2013Ga E-skin for bioelectronics and human\u2013machine interaction","volume":"10","author":"Lopes","year":"2018","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2311597","DOI":"10.1002\/adfm.202311597","article-title":"Liquid Metal-Based Perovskite Solar Cells: In Situ Formed Gallium Oxide Interlayer Improves Stability and Efficiency","volume":"34","author":"Kim","year":"2023","journal-title":"Adv. Funct. Mater."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2310318","DOI":"10.1002\/adfm.202310318","article-title":"Textile-Based Stretchable Supercapacitors with Liquid Metal Current Collectors","volume":"34","author":"Choi","year":"2023","journal-title":"Adv. Funct. Mater."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"453","DOI":"10.1007\/s11814-024-00051-2","article-title":"Optimization of Fabrication Process of Stretchable, Transparent PEDOT:PSS Electrodes for Optoelectronic Applications","volume":"41","author":"Kim","year":"2024","journal-title":"Korean J. Chem. Eng."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2158","DOI":"10.1007\/s11661-021-06256-y","article-title":"A review of liquid metal embrittlement: Cracking open the disparate mechanisms","volume":"52","author":"Norkett","year":"2021","journal-title":"Metall. Mater. Trans. A"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"457","DOI":"10.1016\/S0168-583X(02)01533-1","article-title":"Grain boundary imaging, gallium diffusion and the fracture behavior of Al\u2013Zn Alloy\u2013An in situ study","volume":"199","author":"Tsai","year":"2003","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. B"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1016\/S0921-5093(99)00733-9","article-title":"Penetration of liquid gallium into the grain boundaries of aluminium: A synchrotron radiation microtomographic investigation","volume":"281","author":"Ludwig","year":"2000","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1700024","DOI":"10.1002\/advs.201700024","article-title":"Liquid metal phagocytosis: Intermetallic wetting induced particle internalization","volume":"4","author":"Tang","year":"2017","journal-title":"Adv. Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1114","DOI":"10.1016\/j.snb.2015.07.062","article-title":"Selectively plated stretchable liquid metal wires for transparent electronics","volume":"221","author":"Li","year":"2015","journal-title":"Sens. Actuators B"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3415","DOI":"10.1039\/C7LC00768J","article-title":"An advanced selective liquid-metal plating technique for stretchable biosensor applications","volume":"17","author":"Li","year":"2017","journal-title":"Lab Chip"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"4763","DOI":"10.1038\/s41467-022-32259-3","article-title":"Imbibition-induced selective wetting of liquid metal","volume":"13","author":"Kim","year":"2022","journal-title":"Nat. Commun."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1016\/j.colsurfa.2012.08.056","article-title":"Preparation of magnetic polymer microspheres with reactive epoxide functional groups for direct immobilization of antibody","volume":"414","author":"Pimpha","year":"2012","journal-title":"Colloids Surf. A"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"53789","DOI":"10.1039\/C5RA08788K","article-title":"Advanced analysis of nanoparticle composites\u2013a means toward increasing the efficiency of functional materials","volume":"5","author":"Crick","year":"2015","journal-title":"RSC Adv."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"118847","DOI":"10.1016\/j.carbpol.2021.118847","article-title":"Swelling-based preparation of polypropylene nanocomposite with non-functionalized cellulose nanofibrils","volume":"277","author":"Kim","year":"2022","journal-title":"Carbohydr. Polym."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"154597","DOI":"10.1016\/j.apsusc.2022.154597","article-title":"High aspect ratio copper nanowires and copper nanoparticles decorated by reduced graphene oxide for flexible transparent conductive electrodes","volume":"604","author":"Zhou","year":"2022","journal-title":"Appl. Surf. Sci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"130793","DOI":"10.1016\/j.colsurfa.2022.130793","article-title":"Facile fabrication of super-wettable mesh membrane using locally-synthesized cobalt oxide nanoparticles and their application in efficient gravity driven oil\/water separation","volume":"660","author":"Baig","year":"2023","journal-title":"Colloids Surf. A"},{"key":"ref_27","first-page":"241","article-title":"Flexible graphene-coated carbon fiber veil\/polydimethylsiloxane mats as electrothermal materials with rapid responsiveness","volume":"2","author":"Zhang","year":"2019","journal-title":"Int. J. Lightweight Mater. Manuf."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"12876","DOI":"10.1021\/acsanm.2c02736","article-title":"Copper-nanoparticle-coated fabrics for rapid and sustained antibacterial activity applications","volume":"5","author":"Ku","year":"2022","journal-title":"ACS Appl. Nano Mater."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Liu, Y., Zeng, Y., Zhao, X., Liu, J., and Liu, D. (2021). Analysis of film forming law and characteristics for an air static spray with a variable position of the plane. Coatings, 11.","DOI":"10.3390\/coatings11101236"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Neo, R.G., Wu, K., Tan, S.C., and Zhou, W. (2022). Effect of spray distance and powder feed rate on particle velocity in cold spray processes. Metals, 12.","DOI":"10.3390\/met12010075"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"661","DOI":"10.1038\/nmat1978","article-title":"Imbibition by polygonal spreading on microdecorated surfaces","volume":"6","author":"Courbin","year":"2007","journal-title":"Nat. Mater."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"225601","DOI":"10.1088\/1361-6528\/acbd1f","article-title":"Highly conductive copper films prepared by multilayer sintering of nanoparticles synthesized via arc discharge","volume":"34","author":"Fu","year":"2023","journal-title":"Nanotechnology"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"154422","DOI":"10.1016\/j.apsusc.2022.154422","article-title":"Rapid and low temperature sintering bonding using Cu nanoparticle film for power electronic packaging","volume":"603","author":"Wu","year":"2022","journal-title":"Appl. Surf. Sci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"124567","DOI":"10.1016\/j.colsurfa.2020.124567","article-title":"Strong adhesion of polyvynylpyrrolidone-coated copper nanoparticles on various substrates fabricated from well-dispersed copper nanoparticle inks","volume":"591","author":"Yokoyama","year":"2020","journal-title":"Colloids Surf. 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