dr. nikos kehagias catalan institute of nanoscience and...
TRANSCRIPT
Dr. Nikos Kehagias
Catalan Institute of Nanoscience and Nanotechnology, CSIC and The Barcelona Institute of Science and Technology,
Barcelona, Spain
Euronanoforum- 21-23 June 2017- Malta
A
B
C
D
Nanofabrication NanometrologyMaterials
Courtesy of: www.nanotypos.com
Nanotechnology Value Chain
Hybrid
Hierarchical
Nanopatterning
AdvancedNanomanufacturing
R2R Large Area
Functional
Surfaces
Micro/Nano
Injection
Molding
ICN2 NIL Platform
3 dimensional polymer
structuring
4 mm
Au nanoparticles
35 nm gap
Phononic Crystals400 nm wide nanochannels
200 nm
2D PhC
56 nm
Sub 100 nm Chirped gratings
500 nm
Colloidal crystal growth
Self assemblytemplates
Photonicapplications
Multi levelpatterning
MARKET OUTLOOK
• Global nano-patterinng market is estimated as US$ 1.9 billion in 2015
- projected to reach US$ 19.1 billion by 2020
• NIL represents 82.9% of the total nano-patterning market
• NIL is estimated as US$ 1.6 billion in 2015 - projected to reach US$
13.9 billion by 2020
• UVNIL fastest growing NIL technology representing 72.8% share of
the market in 2015
• UV-NIL market is estimated at US$ 1.4 billion in 2015 - projected to
reach US$ 12.4 billion in 2020
• Hot embossing market is estimated at US$ 144.2 million in 2015 -
projected to reach US$ 1.3 billion in 2020
Data acquired from Nanopatterning – A global market report- 09/15
Intelligent Surfaces
DesignMaster
orginationNIL Applications
a
d
+ +
Process Flow
Value chain
Wetting is a multiscale phenomenon
31/ 10/ 13 14.45Biomimetics inspired surfaces for drag reduction and oleophobicity/ philicity
Side 1 af 16http:/ / www.beilstein- journals.org/ bjnano/ single/ art icleFullText.htm?publicId= 2190- 4286- 2- 9
HOME SUBMISSION MOBILE HELP ADVANCED SEARCH
About | My Journal | Support & Contact | Terms & Conditions Login | Register
Abstract
The emerging field of biomimetics allows one to mimic biology or nature to develop nanomaterials, nanodevices,and processes which provide desirable properties. Hierarchical structures with dimensions of features rangingfrom the macroscale to the nanoscale are extremely common in nature and possess properties of interest. Thereare a large number of objects including bacteria, plants, land and aquatic animals, and seashells with propertiesof commercial interest. Certain plant leaves, such as lotus (Nelumbo nucifera) leaves, are known to besuperhydrophobic and self-cleaning due to the hierarchical surface roughness and presence of a wax layer. Inaddition to a self-cleaning effect, these surfaces with a high contact angle and low contact angle hysteresis alsoexhibit low adhesion and drag reduction for fluid flow. An aquatic animal, such as a shark, is another model fromnature for the reduction of drag in fluid flow. The artificial surfaces inspired from the shark skin and lotus leaf havebeen created, and in this article the influence of structure on drag reduction efficiency is reviewed. Biomimetic-inspired oleophobic surfaces can be used to prevent contamination of the underwater parts of ships by biologicaland organic contaminants, including oil. The article also reviews the wetting behavior of oil droplets on varioussuperoleophobic surfaces created in the lab.
Keywords: aquatic animals; biomimetics; drag; lotus plants; shark skin; superhydrophobicity; superoleophobicity
Top
Introduction
Biologically inspired design, adaptation, or derivation from nature is referred to as ‘biomimetics.’ It meansmimicking biology or nature. Nature has gone through evolution over the 3.8 billion years since life is estimated tohave appeared on the Earth [1]. Nature has evolved objects with high performance using commonly foundmaterials. These function on the macroscale to the nanoscale. The understanding of the functions provided byobjects and processes found in nature can guide us to imitate and produce nanomaterials, nanodevices, andprocesses [2]. There are a large number of objects (bacteria, plants, land and aquatic animals, seashells etc.)with properties of commercial interest.
Natural superhydrophobic, self-cleaning, low adhesion, and drag reduction surfaces
Drag reduction in fluid flow is of interest in various commercial applications. These include transportation vehiclesand micro/nanofluidics based biosensor applications [3]. To reduce pressure drop and volume loss inmicro/nanochannels used in micro/nanofluidics, it is desirable to minimize the drag force at the solid–liquidinterface. A model surface for superhydrophobicity, self-cleaning and low adhesion is the leaves of water-repellentplants such as Nelumbo nucifera (lotus) [2,4-11]. The leaf surface is very rough due to so-called papilloseepidermal cells, which form papillae or microasperities. In addition to the microscale roughness, the surface of thepapillae is also rough, with nanoscale asperities composed of three-dimensional epicuticular waxes which arelong chain hydrocarbons and hydrophobic. The waxes on lotus leaves exist as tubules [10,11]. Water droplets onthese hierarchical structured surfaces readily sit on the apex of the nanostructures because air bubbles fill thevalleys of the structure under the droplet (Figure 1a). Therefore, these leaves exhibit considerablesuperhydrophobicity. Static contact angle and contact angle hysteresis of a lotus leaf are about 164° and 3°,respectively [12,13]. The water droplets on the leaves remove any contaminant particles from their surfaces whenthey roll off, leading to self-cleaning [5] and show low adhesive force [14-16].
Natural superoleophobic, self-cleaning, and drag reduction surfaces
A model surface for superoleophobicity and self-cleaning is provided by fish which are known to be well protectedfrom contamination by oil pollution although they are wetted by water [15,17]. Fish scales have a hierarchicalstructure consisting of sector-like scales with diameters of 4–5 mm covered by papillae 100–300 µm in length and30–40 µm in width [18]. Shark skin, which is a model from nature for a low drag surface, is covered by very smallindividual tooth-like scales called dermal denticles (little skin teeth), ribbed with longitudinal grooves (alignedparallel to the local flow direction of the water) (Figure 1b). These grooved scales reduce vortice formation
TABLE OF CONTENTS Detailed
Abstract
Introduction
Fabrication and Characterization ofBiomimetic Structures for Fluid DragReduction
Modeling, Fabrication andCharacterization ofOleophobic/philic Surfaces
Conclusion
References
Show Album
Biomimetics inspired surfaces for drag reduction and oleophobicity/philicity
Bharat Bhushan
Nanoprobe Laboratory for Bio- & Nanotechnology and Biomimetics (NLB²), The Ohio State University, 201 W.19th Avenue, Columbus, OH 43210-1142, USA
Corresponding author email
This article is part of the Thematic Series "Biomimetic materials".
Guest Editors: W. Barthlott and K. Koch
Beilstein J. Nanotechnol. 2011, 2, 66–84. doi:10.3762/bjnano.2.9
Received 01 Oct 2010 Accepted 20 Jan 2011 Published 01 Feb 2011 Review
ARTICLE INFORMATION
Download References
PART OF THEMATIC SERIES
Biomimetic materials
Figure 1: Two examples from nature: (a) Lotus effect [12], and (b) scale structure of shark reducing drag [21].
Lotus leaf Rose petal
Self- Cleaning Surfaces
Alternative NIL
REVERSE NIL
Inking mode
Intact modeMicrostructures
UV-NILNanostructures
RNIL
Inking modeIntact mode
Hierarchical patterning
Reverse nanoimprint lithography over pre/patterned surfaces
A. Fernández et.al., Design of hierarchical surfaces for tuning wetting characteristics,B. ACS Applied Materials & Interfaces, (2017) Accepted- Manuscript ID: am-2016-13615t.R1
Self- Cleaning Surfaces
Towards 3D hiearchical surfaces
+
Micro structures Nano structures 3D structures
Contact angles [o]
Theoretical Experimental
Surface Structure Wenzel Cassie-Baxter Static Sliding Hysteresis
Microstructure 111 155 145 ± 4 35 ± 5 16 ± 6
Honeycomb pillars 120 110 118 ± 5 Pinned 30 ± 4
Honeycomb lines 120 155 123 ± 9 Pinned 21 ± 10
Nano pillars 144 134 143 ± 2 Pinned 23 ± 4
Nano spikes 146 ± 3 Pinned 45 ± 5
2D surfaces
Hydrophobic Surfaces
Contact angles [o]
Theoretical Experimental
Surface Structure Wenzel Cassie-Baxter Static Sliding Hysteresis
Honeycomb pillars + Micropillars
138 157 156 ± 3 18 ± 3 12 ± 3
Honeycomb lines + Micropillars
138 171 129 ± 5 17 ± 2 10 ± 3
Nano pillars + Micropillars
180 164 165 ± 1 11 ± 4 7 ± 2
Nano spikes + Micropillars
170 ± 2 7 ± 2 4 ± 2
3D-Hierarchical surfaces
Self- Cleaning Surfaces
Self- Cleaning Surfaces
Self- Cleaning Surfaces
Plast4Future TechnologyEnabeling Functional Plastic
Surfaces
Steel Mold
Mold Nano-Patterning
Injection Molding
Plastic Functional products
NANO-Injectionmoulding
Courtesy of NILT Aps.
Colour effects
Easy to paint
Superhydrophobic
Indusrtial Applicsations
Injection moulding
PP
Flat WCA 90 ± 3
WCA 150 ± 3
Sliding 16 ± 3
Hysteresis 15 ± 4
TOPAS
Flat WCA 92 ± 2
WCA 152 ± 2
Sliding 13 ± 3
Hysteresis 10 ± 3
66 % WCA Increasing 65 % WCA Increasing
Nanospikes - Micropillars
Impact velocity Wetting state
0 - 0.7 m/s Lotus State: 167 ± 3°
0.7 – 0.9 m/s Petal State: 151 ± 4°
> 0.9 m/s Wenzel State: 117 ± 5°
Nanopillars - Micropillars
Impact velocity Wetting state
0 - 0.8 m/s Lotus State: 168 ± 2°
0.8 – 1.7 m/s Petal State: 156 ± 3°
> 1.7 m/s Wenzel State: 120 ± 6°
Dynamic Surfaces
Oleophobic Surfaces
Liquids with lower surface tension than water → Overhanging
structures needed
A stable Cassie-Baxter state results only when
Concave structure Convex structure
The traction on the liquid-air interface is downwards due to the capillary
force.
Metal deposition Photolithography
or RNILNickel up-plating Resist removal
PDMS ReplicaOrmocomp UV-NILImprinted overhanging
structures
Can be demolded Cannot be demolded
FABRICATION STEPS
Kinoshita et al., Rep. Prog. Phys. (2008)
N. Bogdanski et al. 3D-Hot embossing of undercut structures – an approach to micro-zippers, Microelectronic Engineering 73–74, 190–195, (2004)
Low density:
3 – 3.5 µm
Medium density:
2 – 2.5 µmHigh density:
0.8 – 1 µm
Water contact angles [⁰]
Surface Structure Static Sliding Hysteresis
Flat surface 112 ± 3 35 ± 3 40 ± 6
Low density 148 ± 3 11 ± 4 10 ± 4
Medium density 155 ± 1 8 ± 2 6 ± 3
High density 147 ± 3 15 ± 3 12 ± 5
Oleophobic Surfaces
Roll-to-Roll Nanometrology
PET film
UV light source
Patterned film
InlineNano
Stamp
Stamp
PET film Patterned film
InlineNano
UV light source
Roll-to-Roll at ICN2
470 nm
430 nm
380 nm
320 nm500 nm
2.5mm
80 mm
20 mm
SEM of a line
470 nm
430 nm
380 nm
320 nm
Line width:
Spacing: 6 µm; Height: 100 nm
Schematics of Silicon Master- A Line Grating -
InlineNano in MOTION
470nm
430nm
380nm
320nm
Variation in rolling speed:
Line Width:
-> The different line width of the grating can be identified up to a rolling speed of 3.0 m per min.
0 10 20 30 40 50 60 70
4
6
8
10
1.0 m/min
2.0 m/min
3.0 m/min
Inte
ns
ity
(a
.u.)
Y (mm)
FLEXPOL project (721062)
• 10 partners
– 4 industrialpartners
– 6 researchpartners
• 36 project months(1/2017 – 12/2019)
• 5,678 Mio. EUR total costs
PILOTS-02-2016Pilot Line Manufacturing of Nanostructured AntimicrobialSurfaces using Advanced Nanosurface FuntionalizationTechnologies"
Blown-extrudedpolypropylene
film withencapsulatedantimicrobialessential oil
Antimicrobialfilms
Product validation in laboraty & hospital
Materials processing
& Nanostructuring
FLEXPOL project (721062)
Investigation ofproduct efficiacy in laboratory and real
hospitalenvironment
Surfaces withhierarchicalmicro- and
nanofeaturesinhibitingmicrobes‘
attachment andgrowth
ACKNOWLEDGMENTS
06/ 04/ 14 18:25Forside - Plast4Future
Page 2 of 2http:/ / www.plast4future.eu/
Partners
http://www.plast4future.eu/ 6 APRIL 2014
Dr. Ariadna FernándezDr. Achille FranconeProf. Clivia Sotomayor Torres
Rose filled microstructure
• In the last years, several new wetting states have been experimentally observed.
• For a hierarchical surface, there can exist nine modes of wetting depending on
whether water penetrates in micro and nanostructures.
• Rose petal effect has a very promising wetting state for different applications,
such as microdroplet transport and localized chemical reactions.
Bhushan, B.; Nosonovsky, M., The rose petal effect and the modes of superhydrophobicity. Philosophical transactions.
Series A 2010, 368 (1929), 4713-28.
Lotus Rose
Cassie Wenzel Wenzel filled microstructure
Cassie filled microstructure Wenzel filled nanostructure Wenzel filled micro/nanostructure
DYNAMIC SURFACES
Intact mode fabricated surfaces
Static contact angle: 167 ± 3 °
Sliding angle: 7 ± 4 °
Hysteresis: 6 ± 3 °
Static contact angle: 168 ± 2 °
Sliding angle: 6 ± 2 °
Hysteresis: 4 ± 2 °
PMMA
Ormocomp
DYNAMIC SURFACES
• Dynamic effects on a superhydrophobic surface analyse energy
barriers responsible of wetting transitions.
• These transitions are directly from a composite to a homogeneous
state.
External stimuli
Lotus state Wenzel state
External
stimuliExternal
stimuli
• Hierarchical surfaces open the pathway for intermediate transitions,
which can be useful if one can get a precise control over them.
Lotus stateWenzel state
Petal state
DYNAMIC SURFACES
M. Nosonovsky et al., Philosophical Transactions of the Royal Society A 374 (2073) (2016).
Extent of gravitational forces relative to capillary
forces acting on the drop
Bond number
LA
glBo
2
Density can induce sagging effect
Liquid Surface Tension(mN/m)
Density(g/m3)
Water 71.99 1
Diiodomethane 50.80 3.32
Ethylene glycol 47.70 1.11
Olive oil 32.03 0.80
30 40 50 60 70
125
130
135
140
145
150
155
Diiodomethane
Ethylene
glycolOlive oil
Water
Co
nta
ct a
ng
le (
0)
Surface Tension (mN/m)
Low density
Medium density
High density
Oleophobic Surfaces
0 20 40 60 80 100
20
30
40
50
60
70
80
Su
rfa
ce
te
nsio
n (
mN
/m)
Ethanol concentration (%)
20 30 40 50 60 70 80
60
80
100
120
140
160
Co
nta
ct an
gle
(0)
Surface tension (mN/m)
≈ 29.7 mN/m
Surface tension threshold for oleophobicity
Wetting No wetting
Oleophobic Surfaces