Single-digit-micrometer thickness wood speaker

• Published in: Nature communications Vol. 10; no. 1; pp. 5084 - 8
• Main Authors: Gan, Wentao, Chen, Chaoji, Kim, Hyun-Tae, Lin, Zhiwei, Dai, Jiaqi, Dong, Zhihua, Zhou, Zhan, Ping, Weiwei, He, Shuaiming, Xiao, Shaoliang, Yu, Miao, Hu, Liangbing
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 08.11.2019; Nature Publishing Group; Nature Portfolio
• Subjects: 639/166; 639/301; 639/301/1005; Acoustic properties; Acoustic resonance; Acoustics; Audio equipment; Densification; Electronic packaging; Humanities and Social Sciences; Mechanical properties; Modulus of elasticity; multidisciplinary; Music; Polypropylene; Science; Science (multidisciplinary); Tensile strength; Thickness; Thin films
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-13053-0

Thin films of several microns in thickness are ubiquitously used in packaging, electronics, and acoustic sensors. Here we demonstrate that natural wood can be directly converted into an ultrathin film with a record-small thickness of less than 10 μm through partial delignification followed by densification. Benefiting from this aligned and laminated structure, the ultrathin wood film exhibits excellent mechanical properties with a high tensile strength of 342 MPa and a Young’s modulus of 43.6 GPa, respectively. The material’s ultrathin thickness and exceptional mechanical strength enable excellent acoustic properties with a 1.83-times higher resonance frequency and a 1.25-times greater displacement amplitude than a commercial polypropylene diaphragm found in an audio speaker. As a proof-of-concept, we directly use the ultrathin wood film as a diaphragm in a real speaker that can output music. The ultrathin wood film with excellent mechanical property and acoustic performance is a promising candidate for next-generation acoustic speakers. Thin films of several microns in thickness are ubiquitously used in packaging, electronics, and acoustic sensors. Here the authors demonstrate an ultrathin wood film with an aligned and laminal structure and acoustic properties which allows application of the film as diaphragm for an audio speaker.