论文标题
边界曲率对稀薄悬浮膜的皱纹的影响
Boundary Curvature Effect on the Wrinkling of Thin Suspended Films
论文作者
论文摘要
在这封信中，我们证明了边界曲率$κ$与边界限制下的薄悬浮膜的皱纹波长$λ$之间的关系。实验是用厚度$ t \ t \ 184 $ 〜nm在玻璃基板上生长的纳米晶体钻石膜进行的。通过在增长后删除部分底物，制作了大约30至811 $μ$ m的圆形边界的悬浮膜。由于残留应力，附加到基材的膜的部分具有压缩的prestrain $ε_0\大约11 \ times 10^{ - 4} $，并且悬浮的膜的部分在其边界上呈方位角皱纹。我们发现，$λ$单调地减少了$κ$，并提出了一个模型，预测$λ\ propto t^{1/2}（ε_0 +ΔRκ）^{ - 1/4} $，其中$ΔR$表示在边界处于边界上的渗透深度。这种关系与我们的实验一致，并且可以适应其他系统，例如植物叶。另外，我们建立了一种测量薄膜中残留压缩应变的新方法。
In this letter, we demonstrate a relation between the boundary curvature $κ$ and the wrinkle wavelength $λ$ of a thin suspended film under boundary confinement. Experiments are done with nanocrystalline diamond films of thickness $t \approx 184$~nm grown on glass substrates. By removing portions of the substrate after growth, suspended films with circular boundaries of radius $R$ ranging from approximately 30 to 811 $μ$m are made. Due to residual stresses, the portions of film attached to the substrate are of compressive prestrain $ε_0 \approx 11 \times 10^{-4}$ and the suspended portions of film are azimuthally wrinkled at their boundary. We find that $λ$ monotonically decreases with $κ$ and present a model predicting that $λ\propto t^{1/2}(ε_0 + ΔR κ)^{-1/4}$, where $ΔR$ denotes a penetration depth over which strain relaxes at a boundary. This relation is in agreement with our experiments and may be adapted to other systems such as plant leaves. Also, we establish a novel method for measuring residual compressive strain in thin films.
