Seo Min-Ho, Choi Seon-Jin, Park Sang Hyun, Yoo Jae-Young, Lim Sung Kyu, Lee Jae-Shin, Choi Kwang-Wook, Jo Min-Seung, Kim Il-Doo, Yoon Jun-Bo
School of Electrical Engineering , Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro , Yuseong-gu, Daejeon 34141 , Republic of Korea.
Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States.
ACS Nano. 2018 May 22;12(5):4387-4397. doi: 10.1021/acsnano.8b00159. Epub 2018 Apr 4.
Nanowire-transfer technology has received much attention thanks to its capability to fabricate high-performance flexible nanodevices with high simplicity and throughput. However, it is still challenging to extend the conventional nanowire-transfer method to the fabrication of a wide range of devices since a chemical-adhesion-based nanowire-transfer mechanism is complex and time-consuming, hindering successful transfer of diverse nanowires made of various materials. Here, we introduce a material-independent mechanical-interlocking-based nanowire-transfer (MINT) method, fabricating ultralong and fully aligned nanowires on a large flexible substrate (2.5 × 2 cm) in a highly robust manner. For the material-independent nanotransfer, we developed a mechanics-based nanotransfer method, which employs a dry-removable amorphous carbon (a-C) sacrificial layer between a vacuum-deposited nanowire and the underlying master mold. The controlled etching of the sacrificial layer enables the formation of a mechanical-interlocking structure under the nanowire, facilitating peeling off of the nanowire from the master mold robustly and reliably. Using the developed MINT method, we successfully fabricated various metallic and semiconductor nanowire arrays on flexible substrates. We further demonstrated that the developed method is well suited to the reliable fabrication of highly flexible and high-performance nanoelectronic devices. As examples, a fully aligned gold (Au) microheater array exhibited high bending stability (10 cycling) and ultrafast (∼220 ms) heating operation up to ∼100 °C. An ultralong Au heater-embedded cuprous-oxide (CuO) nanowire chemical gas sensor showed significantly improved reversible reaction kinetics toward NO with 10-fold enhancement in sensitivity at 100 °C.
纳米线转移技术因其能够以高度简单和高产量的方式制造高性能柔性纳米器件而备受关注。然而，将传统的纳米线转移方法扩展到制造各种器件仍然具有挑战性，因为基于化学粘附的纳米线转移机制复杂且耗时，阻碍了由各种材料制成的不同纳米线的成功转移。在此，我们介绍一种基于材料无关的机械互锁的纳米线转移（MINT）方法，以高度稳健的方式在大型柔性基板（2.5×2厘米）上制造超长且完全对齐的纳米线。对于与材料无关的纳米转移技术，我们开发了一种基于力学的纳米转移方法，该方法在真空沉积的纳米线与下面的母模之间采用可干法去除的非晶碳（a-C）牺牲层。对牺牲层进行可控蚀刻能够在纳米线下方形成机械互锁结构，有助于将纳米线从母模上牢固可靠地剥离下来。使用所开发的MINT方法，我们成功地在柔性基板上制造了各种金属和半导体纳米线阵列。我们进一步证明，所开发的方法非常适合可靠地制造高度柔性和高性能的纳米电子器件。例如，完全对齐的金（Au）微加热器阵列表现出高弯曲稳定性（10次循环）和超快（约220毫秒）的加热操作，加热温度可达约100°C。一个嵌入超长Au加热器的氧化亚铜（CuO）纳米线化学气体传感器对NO的可逆反应动力学有显著改善，在100°C时灵敏度提高了10倍。
