REVIEW SUMMARY
◥MATERIALS SCIENCE
Design and applications of surfaces
that control the accretion of matter
Abhishek Dhyani†, Jing Wang†, Alex Kate Halvey†, Brian Macdonald†, Geeta Mehta, Anish Tuteja*
BACKGROUND:Surfaces that control solid, liq-
uid, or vapor accretion have numerous appli-
cations, including self-cleaning windows and
solar panels; water and fog harvesting; anti-
microbial coatings; ice-shedding coatings for
airplane wings, automobiles, or wind turbine
blades; and enhancing phase-change heat trans-
port during boiling or condensation. The design
of such surfaces has been influenced in part by
numerous natural surfaces that can direct the
accretion of different states of matter. Exam-
ples include water-harvesting cactus spines,
self-cleaning superhydrophobic leaves and
feathers, and prey-trapping slippery surfaces
on carnivorous pitcher plants. Engineered liq-
uid and solid repellent surfaces are often de-
signed to impart control over a single state of
matter, phase, or foulant length scale. However,
surfaces used in different real-world applica-
tions need to effectively control the accrual
of matter across multiple phases and fouling
length scales. For example, ice-shedding sur-
faces must reduce the accretion of foulants
ranging from frost to large blocks of ice; coat-
ings for reducing marine fouling must control
the sequential attachment of soft proteins,
bacteria, algae, mussels, and barnacles; and
medical implant coatings need to prevent foul-
ing from complex bodily fluids, proteins, and
bacterial biofilms. These challenging opera-
tional requirements cause many traditional
surface design strategies for controlling the
accretionofasinglestateofmattertohave
limited practical impact—consider superhy-
drophobic surfaces, which, though effective at
repelling liquid water droplets, are easily fouled
by water vapor or frost in cold environments.ADVANCES:Over the past two decades, surface
design approaches in liquid repellency have
moved from controlling the wetting of a single
high–surface tension liquid, such as water, to
othersingularbutmorechallengingphases,
such as low–surface tension organic liquids.
More recently, surfaces have been developed to
manifest control over dual-phase mixtures, such
as water-oil mixtures, and complex fluids, such
as blood. Similarly, surface design strategies to
control the accretion of different individual
solid foulants have moved from modifying sur-
face chemistry and texture alone to varying
other material properties, including surfacemodulus, mobility, and charge. Solid foulants
display considerable disparity in terms of com-
position, chemical structure, modulus, and the
length scale of deposition, making it challeng-
ing for a single surface design strategy to be
effective against multiple foulants or even a
single foulant under different environmental
conditions. For example, depending on the
environmental conditions, ice displays a wide
disparity in terms of its structure, modulus
(1.7 to 9.1 GPa), density (0.08 to 0.9 g/cm^3 ), and
length scales of fouling (approximately square
nanometers to square meters). Recently, strat-
egies have been introduced to control ice accre-
tion across different environmental conditions
and fouling length scales. These strategies can
also be used to control the attachment of a
myriad of other solid foulants, such as scale,
wax, clathrates, marine foulants, and bacte-
rial biofilms.OUTLOOK:Major strides have been made in
understanding the surface design principles
that control the accretion of specific states of
matter and regulate their phase transitions.
However, in numerous real-world applica-
tions, synergistic accumulation of multiple
states of matter across a wide range of length
scales is common. Overlap in surface design
strategies to control collective solid, liquid,
and vapor accretion is limited, although strat-
egies based on surfaces with high interfacial
mobility, such as tethered polymeric chains
above their glass transition temperature,
and lubricant-infused surfaces have shown
promise in repelling multiple foulants across
different fouling lengths scales. One of the
primary challenges associated with the large-
scale adoption of the different surfaces
discussed here is their mechanical durability,
as many of the coatings developed in the
field thus far utilize materials that can be
easily damaged through abrasion or have poor
adherence to underlying substrates owing to
their low surface energy. Additional challenges
remain in the use of specific chemistries or
coating methods that can restrict scale-up, as
well as the difficulty of directly comparing
the performance of different coatings. Cur-
rent research is aimed at addressing these
challenges and promises a new generation of
surfaces that improve our quality of life, offer
innovative solutions to some of the most im-
portant challenges facing society, and have a
substantial commercial impact, measured in
billions of dollars every year.▪RESEARCH
294 16 JULY 2021•VOL 373 ISSUE 6552 sciencemag.org SCIENCE
The list of author affiliations is available in the full article online.
*Corresponding author. Email: [email protected]
These authors contributed equally to this work.
Cite this article as A. Dhyaniet al.,Science 373 , eaba5010
(2021). DOI: 10.1126/science.aba5010READ THE FULL ARTICLE AT
https://doi.org/10.1126/science.aba5010BloodOmniphobicMulti-liquid repellency Antimicrobial surfacesMarine fouling
releaseTransparent Ice shedding
antifogging materialsEfficient condensationVAPOR^LIQ
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Surfaces that control the accretion of different states of matter.Such surfaces, either individually or in
combination, have a range of commercial applications, including anti-fog surfaces, surfaces that enhance
condensation heat transport, omniphobic surfaces that repel almost all contacting liquids, antimicrobial
surfaces, surfaces that reduce marine fouling, and those that facilitate passive ice-shedding. Such surfaces
can be used in diverse operating environments, including oil pipelines, automotive vehicles, eyewear,
marine vessels, hospital beds, and aircraft. Image created with BioRender.com.