Design and Construction
of 3D Patterning Device for Macro-Molecular Materials:
There are a wide variety of potential applications
for molecular materials of nanometer dimensions arranged through
growth and/or patterning into multi-dimensional nanostructures, and
significant progress has been made in recent years in the production
of these molecular materials. Macro-molecular materials include semiconductor
quantum dots, carbon nanotubes, luminescent and semiconducting polymers,
and metallic nano dots. Macro-molecular biologically active materials
include custom synthesized deoxyribonucleic acid (DNA) oligomers
or monoclonal antibodies able to identify pathogenic antigens. These
materials are promising for the fabrication of electronic devices,
sensors and medical applications. While the synthesis of such molecular
materials has in many cases become a routine process, controlled
assembly of these materials to form well-defined structures is in
many cases quite difficult.
However, controlled and directed assembly
is crucial for the production of custom tailored devices performing
actual tasks like switching or communicating with other components,
or bio-assays/sensors with specific pathogen sensitivity. We believe
that directed assembly (possibly supported by local self-assembly)
represents the key for successful integration of nano-materials into
complex electronic devices or sensors. With the currently built device,
an electrospray based patterning device operating in vacuum (“MoleculeWriter”),
we aim at solving this problem. The schematic design of the MoleculeWriter
is shown in Fig.1. The core design components are the electrospray
unit, which creates an ionized molecular beam directly from solution
inside the vacuum chamber. Through subsequent ion optical elements,
where the electrospray beam can be mass filtered, focused and deflected,
patterns can be written on a substrate. This allows the preparation
of clean 3D structures composed of molecular materials. Future expansion
of the MoleculeWriter will include a fluid distribution capability.
This will offer the opportunity to prepare well-defined structures
composed of a multitude of molecular materials under computer control. |
Fig.1: Preparation of patterned molecular structures
with the MoleculeWriter. Molecular materials in solutions are fed
through the electrospray (ES) device where solvent and solute are
separated and a molecular ion beam is produced. Ion optics and beam
deflectors are used to produce a focused beam that can be scanned
over a substrate surface, allowing the deposition of 3D patterns
to produce structures such as patterned nano-composite layers and/or
individually coated regions of a sensor array.
This system has recently been completed and
demonstrated in our lab. The system is now commercially available.
Please, visit www.elionsystems.com for
more information. |