Biomimetics Smart FabricationsUsman Zubair & Muhammad Irfan

What are Biomematics?

Bio inspired, Bio mimic, Nature inspired, Biomimicry, BionicsWhy nature is the best Teacher?

– design complex – efficient structures– Structures evolved through strict phases to fit the

environmentBio-inspired and bio-enabled materials

Bio-inspired nanomaterials, fibers, composites, functionally graded materials, multifunctional materials, organic-inorganic hybrid composites, adaptive fabrics, biomedical materials; Biological materials vs synthetic bio-inspired materials

Bio-inspired and bio-enabled manufacturingBiomimetic processing, bioclastic processing, self- healing, selfassembly, biomineralization, templating, patterning, hierarchical structures, etc.

Functional bio-inspired surfacesSticking, anti-adhesive, self-cleaning, thermo- and hydro-regulating, anti friction, drag reduction, sound generation, defense surfaces

Bio-insp

ired Approach

es To

Design Smart

Fabric

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Biological materials

Functions

Butterfly wing Superhydrophobicity, directional adhesion, structural color, self-cleaning, chemical sensing capability, fluorescence emission

Brittlestar Mechanical and optical functions

Cicada wing Anti-reflection, superhydrophobicity

Fish scale Drag reduction, superoleophilicity in air, superoleophobicity in water

Gecko foot Reversible adhesive, superhydrophobicity, self-cleaning

Lotus leaf Superhydrophobicity, low adhesion, self-cleaning

Mosquito compound eye

Superhydrophobicity, anti-reflection, anti-fogging

Nacre Mechanical property, structural color

Peacock feather Structural color, superhydrophobicity

Polar bear fur Optical property, thermal insulation

Rice leaf Superhydrophobicity, anisotropic wettability

Rose petal Superhydrophobicity, structural color, high adhesion

Shark skin Drag reduction, anti-biofouling

Spicule Mechanical and fibre-optical properties

Biological materials

Functions

Water strider leg Durable and robust superhydrophobicity

algae eyespot-stigmata

Light reception, reflectance, light sensitivity, response to light

touch-me-not Touch and warmth sensitivity

Mammalian skin Self healing, sensitivities

moth-eye effect Anti reflection

Pine cone Hygroscopic movements

birds Insulation, self cleaning

Plants chloroplasts Solar energy conversion and conservation

Chameleon skin Comuflauge

Spider web Extra ordinary ideas for fabrics under rotational torsions

Fire fly bioluminescence

Velcro Strong adhesiveness

Namib Desert beetle

Hydrophillicity

Spider dragline silk

Mechanical property, supercontraction, torsional shape memory

Spider capture silk Water collection ability, mechanical property, elasticity, stickiness

Anti-dust, Water Repellent, Self Cleaning Fabrics• Glassy Lotus Leaf - clean, anti-dust and water repellent

properties without detergent or spending energy• Special surface topography with super hydrophobicity• Plant’s cuticle soluble lipids, embedded in a polyester

matrix – wax• Microtopography of the lotus leaf exhibit extensive

folding (i.e. papillose epidermal cells) and epicuticular wax crystals jutting out from the plant’s surface, resulting in a roughened micro-texture

• Modern nanoscience and microfabrication techniques• superhydrophobic poly-lactic acid (PLA) fabrics via UV-

photografting of hydrophobic silica particles functionalized with vinyl surface group over silica microstructure

• Superhydrophobic cotton fabrics include different techniques modified silica sols, co-hydrolysis and polycondensation of different silanes and silicates, treatment with densely packed aligned carbon nanotubes and PAN nanofibers

Lotus Leaf Microfabrication Model

Light Sensitive Apparel

• Light reception and reflectance in plants provides a novel strategy of photosensing at higher level of sophistication to perform shape recognition, stereo and locomotion, responding to changing directions of lights.

• Chlamydomonas sps. swims forward as well as backward in response to harmful UV radiation, equipped with a flagellate engine called eyespot or stigmata

• photosensitive optical polymers fibers that can be successfully integrated into textiles

• Strategy involves making gratings of polymethylmethacrylate (PMMA) cladding and methyl methacrylate copolymer cores. This methacrylate core-clad doped with benzyl methacrylate co-monomer (with strong UV absorption) containing a photo-initiator benzophenone and trans-4-stilbenemethanol (a molecule which undergoes photoisomerization).

• This hierarchical assembly exhibits stigmata like sensitivity and can be applied to block UV rays from light, protecting skin and soft tissues

Algae Eyespot or stigmata Design

Touch Sensitive Apparel • Touch sensitive plant Mimosa pudica shows human

muscle’s actin–myosin like quick sensing and actuation with its leaf-moving muscle, so-called pulvinus which performs touch sensitive hydraulic actuation.

• autonomous organ, housing mechano- and photoreceptors

• specialized cells undergo visible swelling and shrinking, actuated by changes in turgor pressure and rapid growth expansion across leaf epidermis involving ion transport

• Micro analogous of extension and flexion movement in human and animals – triggering of these cells make by uptake of K+ ions

• design fabrics which shrink and de-shrink in response to external stimuli such as touch, sound and/or light

• wearable fabrics equipped with actuators and sensors perform artificial massaging and aromatizing functions while walking

• haptic fabrics by knitted smart materials with touch therapy features

• Electrotherapy and neurotherapy garments

Touch-me-not Pulvinus Design

Smart Breathing Fabrics• The scales of seed-bearing pine cones move in

response to changes in relative humidity• hygroscopic movement is motivated by a structural–

functional mechanism at the base of each seed petal or scale

• When dries, automatically opens up by moving away the scales gape, facilitating release of the cone’s seed when kept in moist (damp) environment, scales close up

• cones reveal two types of scale growing from the main body of the cone— the ovuliferous scale (sclerenchymatous (cellulose) fibers) and the bract scale

• Designing humid sensitive adaptive cloth• The fabric design utilizes two layers: one of thin spikes

of wool, another water absorbent material which opens up when gets wet by the wearer’s sweat, like ovuliferous scale in pine

• the layer dries out, the spikes automatically close up again

• Second layer protects the wearer from the rain taking dry air in while closing the fabric pores and moist air out while opening

• Such fabric could adapt to changing temperatures by opening up when warm and shutting tight when cold

Pine Cone Inspired Hygroscopic Movements Design

Camouflage Apparel - Cryptic Coloration• Fish and Chameleon skin - specialized layer of cells

under their transparent outer skin filled with chromatophores or alternating layers of xanthophore, iridophores, guanine crystals

• A layer of dark melanin housed in melanophores is situated in deeper skin layers and contains reflective iridophores, which exhibits phenomenal camouflage

• Specialized cells filled with pigment granules are located in cytoplasm, and their beauty of the color changing lies in the efficient dispersion of the pigment granules as per changing intensity of incident light

• This nature’s cryptic phenomenon inspired to design choleric liquid crystals (CLCs) to alter the visible color of an object to create the thermal and visual camouflage in fabrics.

• CLCs color can be changed with temperature sensitive thermocouples. Heating–cooling ability of thermocouples used to adjust the color of CLC to match the object’s background color

• Optical camouflage in fabric design to develop and impregnate optical phased array (OPA) - use of spatial light modulators to steer light beams like holographic designs in three dimensional hologram of background scenery

Chameleon Skin, Fish Scale Derived Material Design

Self Healing Fabrics• Healing process in mammals -complex and involves

hemostasis (arrest of bleeding), inflammation (recruiting immune cells to clear of any microbial population and cell debris), proliferation (growth of new tissue), and remodeling (retaining tissue shape like before injury) spontaneously and autonomously

• An important aspect is rapid hemostatic response to arrest the bleeding and remainder very complex and lengthy process

• nature’s healing machinery inspired different healing concepts offer the ability to restore mechanical performance of materials via fusion of the failed surfaces

• Microcapsules reinforced with hollow fibers, polymer composites - lightweight, high stiffness and superior elastic. Microencapsulation of self-healing components involves the use of a monomer, dicyclopentadiene (DCPD), in urea–formaldehyde microcapsules dispersed within a polymer matrix.

• Microcapsules ruptured by a progressing crack, monomer is drawn along the fissure where it comes in contact with a dispersed particulate catalyst (ruthenium based ‘Grubbs’ catalyst), initiating polymerization, thus repair the crack.

Nature’s Healing Mechanism In Mammalian Tissue

Designing E-circuited Luminescent Fabrics• Light production (glow) in fireflies arises on account of

an enzyme catalyzed bio-chemical reaction called bioluminescence

• The enzyme luciferase acts on luciferin, in the presence of magnesium ions (Mg2+), adenosene triphosphate (ATP) and oxygen to produce light

• Chemical process incites motivation to design glowing clothes in dark to add valuable assets to fabrics and textile industry

• e-fabric design• Researchers able to produce the light-emitting devices

with fabric printed circuit boards (PCBs) and successfully connect them with wearable display format using socket buttons

• Small light-emitting sources (LESs) are attached randomly to the fabric with Velcro brushes at their ends. When both ends of the LESs are brushed against the power and ground planes

• Philips’ Lumalive fabrics with flexible arrays of colored light-emitting diodes (LEDs) fully integrated into the fabric, without compromising the softness or flexibility of the cloth

Firefly Glowing Model

Anti-tear Fabrics: Apparel With Spiderman’s Suit Mechano-elasticity• Proteinaceous spider silk - natural silk with unique

material properties with unparalleled combinations of stiffness, strength, extensibility and toughness, exploiting hierarchical structures

• Nanoscale crystalline reinforcement – stiff nanometer sized crystallites embedded and dispersed in softer protein matrices

• Synthetic nanoreinforced structure from natural spider silk - an opportunity to synthesize and conjugate polymer nanocomposites in fabrics to potentially rival the most advanced materials in nature.

• New solvent-exchange approach that is amenable with current textile industry, engineers reinforce the hard microdomains of commercial polyurethane elastomer with tiny clay discs (about 1 nm, or a billionth of a meter thick and 25 nm in diameter).

• This reinforced molecular nanocomposite is that it can be easily tuned to make fibers similar to stretchy compounds such as nylon or Lycra for traditional textile industry

Spider Silk Inspired Design

High Efficiency Swimsuits Design With Antibacterial Effect• Shark - high efficiency swimming and buoyancy due to

special ingenious anti-drag design of their skin which reduces drag by 5–10% move swiftly in water at the cost of low energy expenditure

• SEM - tooth-like scales, (dermal denticles or riblets), ribbed with longitudinal grooves vertical vortices or spirals of water, keeping the water closer to the shark’s body, reducing the surface drag

• unique shark scale featured microtopography that acts as antibacterial fouling surfaces and microorganisms find it inhospitable to attach on such grooved surface

• tightly fitting suits, covering a large area of the body are made up of fabrics which are designed to mimic the properties of a shark’s skin by superimposing vertical resin stripes. Riblet effect

• Swimsuits with the new fibers and weaving techniques mimicking shark scales microfeatures, produced to cling tightly to the swimmer’s body give the wearer a 6-m equivalent head start in swimming competition by dampening turbulence in the immediate layer of water, next to the skin

• designing antimicrobial fabrics without the chemical treatments, microtextured fabric called Sharklet to explore the ‘‘surface topography’’ which repels the germ

Shark Skin Inspired Low Hydrodynamic Surface Drag Design

Thermo- and Pressure Sensitive Fabric• Mammalian skins - provide protection (epidermis) and

regulate thermomechanical and emotional (pain) environment of the body surface via multiple sensing capabilities

• sensors - in form of arrays, estimated to have 50 receptors per 100 square mm giving fine spatial resolution and high sensitivity

• artificial stimuli responsive smart fabrics• Developments in microelectromechanical systems

(MEMS) and nanoelectromechanical systems (NEMS) - design smart sensors can be designed and coupled with fabrics in array format

• Patch antenna printed on a flexible semiconducting substrate which acts as engineered sensor skins, sense of pain via strain measurement of surrounding. For direct health monitoring and data mining-transmission for personalized medical care

• an analogous skin like sensor exhibits flexibility, self-healing and damage sensing functionalities. Using microfabrication techniques, a substrate of copper-clad polyimide sheets arranged in a layer-by-layer format, using polyimide sheets and an UV curable epoxy - structural adhesive and self-healing fill material

• LC circuits senses the damage site • self healing polymer loaded with drug.

Mammal Skin Inspired Design

Source

• Ajay V. Singh, Anisur Rahman, N.V.G. Sudhir Kumar, A.S. Aditi, M. Galluzzi, S. Bovio, S. Barozzi, E. Montani, D. Parazzoli “Bio-inspired approaches to design smart fabrics” J Mater Design (2011).

• Meoli D, May-Plumlee T. Interactive electronic textile development: a review of technologies. JTATM 2002;2(2)

• Biggins PD, Kusterbeck A, Hiltz JA. Bio-inspired approaches to sensing for defence and security applications. Analyst 2008