Nanocontact Electrification: Patterned Surface Charges Affecting Adhesion, Transfer, and Printing
Nanocontact Electrification: Patterned Surface Charges Affecting Adhesion, Transfer, and Printing
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DOI：
10.1021/la200773x
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发表时间：
2011-06-07
期刊：
影响因子：
3.9
通讯作者：
Jacobs, Heiko O.
中科院分区：
文献类型：
--
作者：
Cole, Jesse J.;Barry, Chad R.;Jacobs, Heiko O.
接触带电产生了一个看不见的标记，传统的表面光谱测量忽略了这一点，而且往往无法检测到。它在静电放电过程中对我们的日常生活产生宏观影响，在软光刻、转印和印刷等领域也同样与纳米级相关。这份报告描述了一种新的概念方法来研究和利用接触带电，而不是以前的表面作用力装置和点接触实施。我们的过程研究的不是单点接触，而是发生在多个不同大小和形状的纳米接触之间的纳米接触带电，这些接触可以使用柔性材料，特别是表面功能化的聚二甲基硅氧烷(PDMS)邮票和其他常见的介电材料(PMMA、SU-8、PS、PAA和SiO_2)形成。当形成共形接触和强迫分层时，接触区域变成带电区域，这是用开尔文探针力显微镜直接观察到的，揭示了横向分辨率低于100 nm的电荷图像。实验表明，化学驱动的界面质子交换是迄今所研究的材料的主要充电机制。记录的未补偿电荷水平接近理论极限，这是由表面分层时形成的气隙的介电击穿强度设定的。使用包括天平和微操作器的力距离曲线测量来记录电荷的宏观存在，以控制分层对象之间的距离。脱层表面之间的库仑引力达到150N/m(2)。在如此大的范围内，力得到了许多应用。我们展示了印刷电荷在(I)纳米印刷术和(Ii)纳米转移印刷领域的应用，其中最小的物体直径类似于10纳米，而最大的物体在毫米到厘米的范围内。印刷的电荷也会影响接触表面的电子性质。例如，在绝缘体上硅的情况下，场效应晶体管与PDMS接触，随后的分层导致阈值电压漂移超过500 mV。
Contact electrification creates an invisible mark, overlooked and often undetected by conventional surface spectroscopic measurements. It impacts our daily lives macroscopically during electrostatic discharge and is equally relevant on the nanoscale in areas such as soft lithography, transfer, and printing. This report describes a new conceptual approach to studying and utilizing contact electrification beyond prior surface force apparatus and point-contact implementations. Instead of a single point contact, our process studies nanocontact electrification that occurs between multiple nanocontacts of different sizes and shapes that can be formed using flexible materials, in particular, surface-functionalized poly(dimethylsiloxane) (PDMS) stamps and other common dielectrics (PMMA, SU-8, PS, PAA, and SiO2). Upon the formation of conformal contacts and forced delamination, contacted regions become charged, which is directly observed using Kelvin probe force microscopy revealing images of charge with sub-100-nm lateral resolution. The experiments reveal chemically driven interfacial proton exchange as the dominant charging mechanism for the materials that have been investigated so far. The recorded levels of uncompensated charges approach the theoretical limit that is set by the dielectric breakdown strength of the air gap that forms as the surfaces are delaminated. The macroscopic presence of the charges is recorded using force distance curve measurements involving a balance and a micromanipulator to control the distance between the delaminated objects. Coulomb attraction between the delaminated surfaces reaches 150 N/m(2). At such a magnitude, the force finds many applications. We demonstrate the utility of printed charges in the fields of (i) nanoxerography and (ii) nanotransfer printing whereby the smallest objects are similar to 10 nm in diameter and the largest objects are in the millimeter to centimeter range. The printed charges are also shown to affect the electronic properties of contacted surfaces. For example, in the case of a silicon-on-insulator field effect transistors are in contact with PDMS and subsequent delamination leads to threshold voltage shifts that exceed 500 mV.