Department of Materials Science and Engineering, University of Maryland, College Park, MD, 20742, USA.
Department of Mechanical Engineering, University of Maryland, College Park, MD, 20742, USA.
Nat Commun. 2019 Nov 8;10(1):5084. 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.
厚度为数微米的薄膜在包装、电子和声学传感器中被广泛应用。在这里，我们证明天然木材可以通过部分脱木质素和致密化直接转化为厚度小于 10μm 的超薄薄膜。得益于这种对齐和层压结构，超薄木膜具有出色的机械性能，拉伸强度高达 342MPa，杨氏模量为 43.6GPa。这种材料的超薄厚度和卓越的机械强度使其具有出色的声学性能，其共振频率比音频扬声器中使用的商用聚丙烯振膜高 1.83 倍，位移振幅高 1.25 倍。作为概念验证，我们直接将超薄木膜用作扬声器中的振膜，该扬声器可以输出音乐。这种具有优异机械性能和声学性能的超薄木膜是下一代声学扬声器的有前途的候选材料。
