PDMS Deposition for Optical Devices by Dip‐Pen Nanolithography

Abstract

Dip‐pen nanolithography (DPN) is a low‐cost, versatile bench‐top method for directly patterning materials on surfaces with sub‐50 nm resolution; it involves the use of a cantilever tip to transfer a selected ink onto various surfaces to create predefined patterns. Many parameters may influence DPN quality, due to the variety of deposited and surface materials and the chemical interactions between them. DPN tip deposition of liquid inks is not yet well understood, due to the lack of thorough study of the various parameters that need to be controlled in order to achieve uniform patterning. In this research, the printing of polydimethylsiloxane (PDMS) lines and the control of their physical dimensions are investigated; the applied parameters are different humidity levels, n‐hexane dilution proportions and different tip velocities. Numerous experiments accompanied by atomic force microscope measurements are conducted in order to derive a recommended recipe for the required dimensions of the printable lines. A practical aspect of the research is to assess the potential of the application of DPN for the fabrication of various optical devices, such as gratings and waveguides. In order to validate the theoretical results, PDMS printing over silicon is used to successfully produce an optical diffraction grating.

Controlling the Size and Pattern Pitch of Ni(OH)2 Nanoclusters Using Dip-Pen Nanolithography to Improve Water Oxidation

“…The hydroxyl anions have two roles in this process; one in nickel oxidation (Reaction ( 3 )) and another in oxygen formation (Reaction ( 5 )). For Reaction ( 3 ) to be efficient, the surface area of the Ni(OH) 2 clusters needs to be large, such that more hydroxyl anions are consumed per cluster and will react more easily and with a higher probability with Ni(OH) 2 [ 31 ]. For Reaction ( 5 ) to be efficient, the pattern pitch dimensions needs to be ideal, so as to allow the two hydroxyls to encounter each other with a sufficiently high probability [ 27 ].…”

“…We propose a novel, simple, and cost-efficient method for the accurate patterning of uniform, nano-sized catalyst clusters, using minute amounts of the catalyst [ 31 ]. We employ the NLP2000 (NanoInk, Inc.) dip-pen nanolithography (DPN) platform [ 31 ], which enables tight control over the size of the clusters and the pattern pitch dimension, as well as over the concentration of the catalyst clusters. Notably, the same method can be used to pattern any active material [ 31 ], and is, therefore, relevant to numerous applications—including the OER.…”

“…We employ the NLP2000 (NanoInk, Inc.) dip-pen nanolithography (DPN) platform [ 31 ], which enables tight control over the size of the clusters and the pattern pitch dimension, as well as over the concentration of the catalyst clusters. Notably, the same method can be used to pattern any active material [ 31 ], and is, therefore, relevant to numerous applications—including the OER. Here, as a model catalyst for the OER, we chose to use Ni(OH) 2 —a cheap and widely used catalyst in this process [ 21 , 26 , 32 , 33 , 34 , 35 , 36 , 37 ]—although the proposed method can be used to pattern a wide range of catalysts.…”

“…In addition, while most meta-surfaces are made of semiconductor materials and metals [ 40 , 41 ], MCSs can be manufactured from liquid inks, including polymers, proteins, and, as shown in this work, salt solutions. To pattern the catalyst on the surface, we used the accurate and affordable DPN technique—here, employing the NLP2000 DPN tool [ 31 ].…”

Large‐Scale Micropillar 3D Patterning with High‐Aspect Ratio Using a Theta‐Pipette

“…Therefore, micro-nano technology still faces many challenges in the development of technology for manufacturing structurefree microstructures. The scanning probe microscopy (SPM) method for maskless deposition has been widely reported in recent years, [7][8][9][10][11][12] in which the probe tip is used to manipulate materials directly to fabricate micro-nano structures without the need for templates or postpositioning operations. Surface processing techniques that use SPM technology mainly include nano-ion accumulation, [13,14] electrodeposition, [15] material removal based on scratches or thermal desorption, [16] local electroplating/electrolysis of ultramicroelectrodes, [17][18][19] and micro-nano pipette local material transfer.…”