In this paper, we review the current development of stencil lithography for scalable micro- and nanomanufacturing as a resistless and reusable patterning technique. We first introduce the motivation and advantages of stencil lithography for large-area micro- and nanopatterning. Then we review the progress of using rigid membranes such as SiNx and Si as stencil masks as well as stacking layers. We also review the current use of flexible membranes including a compliant SiNx membrane with springs, polyimide film, polydimethylsiloxane (PDMS) layer, and photoresist-based membranes as stencil lithography masks to address problems such as blurring and non-planar surface patterning. Moreover, we discuss the dynamic stencil lithography technique, which significantly improves the patterning throughput and speed by moving the stencil over the target substrate during deposition. Lastly, we discuss the future advancement of stencil lithography for a resistless, reusable, scalable, and programmable nanolithography method.

The authors present a high-throughput fabrication technique to create a large-area graphene nanomesh (GNM). A patterned negative photoresist layer was used as an etch mask atop chemical vapor deposition grown graphene on Cu foil. Shielded by the periodic nanopatterned photoresist mask, the graphene layer was selectively etched using O2 plasma, forming a GNM layer. A poly(methyl methacrylate) layer was spun on the GNM atop copper foil, and the GNM was subsequently transferred onto a SiO2/Si substrate by etching away the copper foil. Large-area (5 × 5 cm), periodic (500 and 935 nm in pitch), uniform, and flexible GNMs were successfully fabricated with precisely controlled pore sizes (200–900 nm) and neck widths (down to ∼20 nm) by adjusting the pattern generation of holographic lithography and the O2 plasma etching process parameters. This holographic lithography-based transfer method provides a low-cost manufacturing alternative for large-area, nanoscale-patterned GNMs on an arbitrary substrate.

Stretchable electrodes are a critical component for flexible electronics such as displays, energy devices, and wearable sensors. Carbon nanotubes (CNTs) and graphene have been considered for flexible electrode applications, due to their mechanical strength, high carrier mobility, and excellent thermal conductivity. Vertically aligned carbon nanotubes (VACNTs) provide the possibility to serve as interconnects to graphene sheets as stretchable electrodes that could maintain high electrical conductivity under large tensile strain. In this work, a graphene oxide (GO)-VACNT hybrid on a PDMS substrate was demonstrated. Here, 50 μ m long VACNTs were grown on a Si/SiO ₂ wafer substrate via atmospheric pressure chemical vapor deposition. VACNTs were directly transferred by delamination from the Si/SiO ₂ to a semi-cured PDMS substrate, ensuring strong adhesion between VACNTs and PDMS upon full curing of the PDMS. GO ink was then printed on the surface of the VACNT carpet and thermally reduced to reduced graphene oxide (rGO). The sheet resistance of the rGO-VACNT hybrid was measured under uniaxial tensile strains up to 300% applied to the substrate. Under applied strain, the rGO-VACNT hybrid maintained a sheet resistant of 386 ± 55 Ω/sq. Cyclic stretching of the rGO-VACNT hybrid was performed with up to 50 cycles at 100% maximum tensile strain, showing no increase in sheet resistance. These results demonstrate promising performance of the rGO-VACNT hybrid for flexible electronics applications.