Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States.
ACS Nano. 2011 Jan 25;5(1):672-8. doi: 10.1021/nn103189z. Epub 2010 Dec 28.
Silicon (Si) nanowire (NW) coils were fabricated on elastomeric substrates by a controlled buckling process. Si NWs were first transferred onto prestrained and ultraviolet/ozone (UVO)-treated poly(dimethylsiloxane) (PDMS) substrates and buckled upon release of the prestrain. Two buckling modes (the in-plane wavy mode and the three-dimensional coiled mode) were found; a transition between them was achieved by controlling the UVO treatment of PDMS. Structural characterization revealed that the NW coils were oval-shaped. The oval-shaped NW coils exhibited very large stretchability up to the failure strain of PDMS (∼104% in our study). Such a large stretchability relies on the effectiveness of the coil shape in mitigating the maximum local strain, with a mechanics that is similar to the motion of a coil spring. Single NW devices based on coiled NWs were demonstrated with a nearly constant electrical response in a large strain range. In addition to the wavy shape, the coil shape represents an effective architecture in accommodating large tension, compression, bending, and twist, which may find important applications for stretchable electronics and other stretchable technologies.
硅（Si）纳米线（NW）线圈通过受控的屈曲过程在弹性体衬底上制造。首先，将 Si NW 转移到预拉伸和紫外线/臭氧（UVO）处理的聚二甲基硅氧烷（PDMS）衬底上，并在释放预拉伸时发生屈曲。发现了两种屈曲模式（平面波浪模式和三维螺旋模式）；通过控制 PDMS 的 UVO 处理可以实现它们之间的转换。结构表征表明，NW 线圈呈椭圆形。椭圆形 NW 线圈表现出非常大的拉伸性，直到 PDMS 的失效应变（在我们的研究中约为 104%）。这种大的拉伸性依赖于线圈形状在减轻最大局部应变方面的有效性，其力学类似于螺旋弹簧的运动。基于螺旋 NW 的单个 NW 器件在大应变范围内表现出几乎恒定的电响应。除了波浪形，线圈形状还代表了一种有效的架构，可以适应大张力、压缩、弯曲和扭转，这可能在可拉伸电子产品和其他可拉伸技术中找到重要应用。
