The field of microfluidics covers a broad range of
applications that deal with the motion of fluids at a micro-scale.
Microfluidic systems comprising nozzles, pumps, reservoirs, mixers, valves,
etc., can be used for a variety of applications including drug dispensing,
ink-jet printing and general transport of liquid, gases and their
mixtures. The field of microfluidics has entered an exciting stage of
development and growth, and new discoveries are being made every day.
The invention presented here teaches how to construct a
microfluidic device so that water and other fluids can be manipulated as drops
or within microchannels using light. The basic elements of the invention
include: (1) photoresponsive molecule; (2) film coating that maintains
photoresponsivity of the molecule when applied to a surface and that permits
light-induced control of wetting, surface energy; and (3) proper manipulation of
surface roughness in order to magnify the photoresponsive contact angle change
and to overcome contact angle hysteresis which would normally prevent water and
other liquids from being driven by light.
For this new discovery, the ASU team theorized and proved
that a change in water wettability – the ability of water molecules to easily
move across a surface – when induced by light can be significantly amplified
through a combination of very high nanoscale roughness and chemically coating
the surface with molecules. The primary advance came with the realization
that if the surface was roughened at the nanoscale, the ‘Lotus leaf effect’
could be obtained, and the small change in water repelling controlled by light
could be magnified to a level that overcame hysteresis.
Development
Interdisciplinary research and development in microfluidics
is gaining momentum at Arizona State University and across a number of related
fields such as biodiagnostics, fuel cells, and MicroElectroMechanical Systems
(MEMS). Active research continues in this area at ASU. At this time, AzTE is
seeking potential collaborative and licensing partners for this
technology.
Potential Applications
- Biological Testing
- Chemical Analysis
- Drug Delivery & Pharma Research
- Movement of Liquids at sub-µL volumes
- Microreactor Feeds
- Microseparation and Purification
- Microprocessing of Liquids
- Non-mechanical Fluidic Valves
Benefits and Advantages
- Placement of microdroplets in predetermined positions for
analysis
- Relatively inert process
- No potentially damaging electric fields
- No air bubbles that can denature proteins
- No moving parts that are expensive to make &
difficult to repair
- Regulate the flow of fluid on surfaces or in channels
Download
original PDF
For more information about the inventor(s) and their
research, please see
Dr. Gust's
departmental webpage
Dr. Gust's research webpage
Dr. Hayes'
departmental webpage
Dr. Hayes' research
webpage
