Repeatable and High-Efficiency Patterning of Silver Nanowires on PDMS Using Micromilled Aluminum Molds

Abstract

We present an inexpensive, repeatable, and efficient method of patterning silver nanowires onto polydimethylsiloxane (PDMS) using a mold-based approach. A micromilling machine is used to prepare an aluminum mold with a raised pattern so that PDMS cured in these molds is imprinted with the design. A solution of silver nanowires and ethanol can then be injected into the pattern. This method can be used to pattern silver nanowires onto PDMS in any two-dimensional (2D) layout, meaning it can be extended to produce a wide range of PDMS/silver nanowire-based sensors and devices. We demonstrate this by the development of two separate patterns. An intricate logo is developed in order to demonstrate the capability of patterning curved and sharp edges, and a strain gauge is developed in order to demonstrate a functional device.

The development of a pressure sensor using a technique for patterning silver nanowires on 3-dimensional curved PDMS membranes

“…Typically, ethanol and PDMS have a low affinity which would cause the solution to distribute unevenly on the substrate [10]. It has been shown previously that by surface treating PDMS with corona surface treatment or oxygen plasma, the affinity between PDMS and ethanol increases resulting in a more evenly distributed AgNW network [7,26,27]. After surface treatment, AgNW/ethanol solution with a concentration of 5 mg ml −1 was deposited by a pipette in 100 µl increments.…”

“…Flexible electronic materials have generated substantial research interest due to their potential applications in a variety of sensors and devices including touch screens, strain gauges, and tactile pressure sensors, as well as wearable devices like hydration sensors, ECG sensors, and temperature sensors [1][2][3][4][5][6][7][8][9][10][11][12]. Embedding conductive nanoparticles (such as silver nanowires (AgNWs), copper nanowires, or carbon nanotubes) in a flexible substrate is one way to form a composite material which is flexible and conductive [1-5, 11, 13-16].…”