Personalized antimicrobial and soundproof earplugs through embedded-suspension 3D printing of polydimethylsiloxane-Ag composites for the prevention of swimmers’ otitis externa

Aquatic activities, particularly swimming, have been demonstrated to enhance physical conditioning and psychological well-being. However, the risk of water-induced otitis externa—caused by microbial colonization in the external auditory canal—often deters sustained participation in aquatic sports. Traditional swimming earplugs are typically limited in terms of comfort, water resistance, and antimicrobial protection, which can lead to potential ear canal infections and reduced effectiveness in preventing water ingress. In this study, we proposed using 3D scanning and printing technology to produce personally customized swimming earplugs to address these challenges. Embedded-suspension 3D printing technology was applied to fabricate structures using non-self-supporting Polydimethylsiloxane (PDMS) ink, printing hydrophobic ink in a hydrophilic system. The 3D-printed PDMS/Ag-3% composites exhibited an excellent inhibition rate (99.89%), good sound insulation performance (>30 dB, 1000–6300 Hz, 8 mm thickness), elasticity (elongation at break of 62.93%), and low modulus (0.85 MPa). We then recruited 60 beginner swimmers for a wear trial to demonstrate the effectiveness of personalized earplugs in preventing otitis externa and reducing ear canal irritation. This approach not only highlights the potential of 3D printing technology in sports equipment but also offers new insights for developing customized wearables.

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