Mars Desert Research Station

Abstract: Most data today, including pictures, videos, documents, technical data, etc., is stored digitally. Much of this information is of great importance both to individuals, e.g., pictures and video, and to governmental organizations and corporations, e.g., documents and technical data. Unfortunately, almost all of the data storage options available today show high degrees of volatility – they are for the most part ephemeral, lasting in general only a few years to about a decade.1 Our group has been actively working in this area to develop new materials and data storage options that will offer greater permanence. In particular, we have recently been developing permanent solid-state storage devices that use nanofuses as the basic storage elements. Clearly, to be competitive with current data storage densities, features sizes will need to be around those in current Flash technology. Accordingly, tools are need for prototyping at these dimensions. Here we will present electron beam lithography as an effective patterning/prototyping tool for this kind of work, and then describe its use in the fabrication of contact pads and carbon nanofuses for permanent solid-state storage devices.

Abstract: We describe the direct, conformal, atomic layer deposition (ALD) of silica onto carbon nanotubes (CNTs) in the microfabrication of thinlayer chromatography (TLC) plates. As before, these plates were prepared with zig-zag hedge and channel microstructures, with high aspect ratio, porous hedges. After ALD, scanning electron microscopy (SEM) showed an increase in the radius of the CNTs of 8–40 nm. X-ray photoelectron spectroscopy (XPS) showed that the plates were composed almost entirely of silicon and oxygen, without contamination of metals or other elements that might compromise chromatographic performance, e.g., aluminum. Time-of-flight secondary ion mass spectrometry confirmed the extremely low level of aluminum in the plates. The final TLC layer thickness was ca. 50 μm. Separations of a test mixture of dyes from CAMAG (Muttenz, Switzerland) on an uncoated silica plate under traditional, normal phase conditions gave efficiencies of 40,000–140,000 plates m⁻¹ with migration distances ranging from 2 to 36 mm. A separation of two fluorescent dyes, eosin Y disodium salt and sulforhodamine B, on an amino silane-coated plate gave efficiencies of ca. 170,000 and 200,000 plates m⁻¹, with hR_F values of 76 and 88, respectively. Run times on these new plates were much faster than on conventional TLC plates.