M -C TEXTILE Meta Cooling

META-COOLING TEXTILEPerformance TeamYuHuang Wang (PI) Min Ouyang(Chemistry)(Physics)Bao Yang(Mech. Eng.)Bing Hu(MSE)Shulong LiEdmir SilvaMin LiSenior Scientist and Corporate Product DevelopmentPostdoctoral leadInnovation Lead, Unifi Manufacturing, Inc.Milliken & CompanyDuration of Award: May 1, 2015-April 30, 2018meta cooling

META COOLING TEXTILE WITH SYNERGETIC INFRARED RADIATIONAND AIR CONVECTION FOR BIDIRECTIONAL THERMOREGULATIONmeta coolingTechnology Summary Active infrared properties control in clothing, for the firsttime, through innovative meta-fiber technology. Self-powered autonomous regulation of clothing forthermal comfort. Maximize the efficiency of localized cooling/warmingthrough synergetic actions of all 4 major mechanisms.Value Proposition A unique new function for clothing to help penetrate the 600B global industry of apparel. Potential to reduce energy cost of buildings that can total2% of all energy used in the United States.Uniqueness ClaimMetricState of the ArtProposed(air conditioned clothes) Added ThermoregulationCapacityN/A41 WSelf-regulationNoYes2.5 -5 W0Weight Increase 10%2.5%Cost Increase per T-shirt 100 0.88 - 3.42Power Consumption MCT integrates nanostructures with ideal thermalband and responsive inter-coupling to effectivelymanage thermal comfort by synergetic controlover infrared radiation and the other heatexchange channels.When hot, the yarns shrinks, the nanostructuresinteract to maximize emission, the body coolseffectively. When cold, the reverse effects occur.Efficient LTMS with bidirectional thermoregulation at a fraction of cost.Patents pending

MCT vs. State-of-the-ArtWearable LTMS meta coolingCooling vests (including evaporative cooling)Sweat wicking (e.g. Nike Sphere React and AeroReact)Air‐conditioned jacketsDisadvantages (air-conditioned jackets specifically):– Bulky (require 2 fans, control box, cable, and 4 AA batteriesevery 5 hours)– Costly ( 140 or more per system)– One direction regulation/lackof infrared controlNike AeroReact (Oct. 2015)Kuchofuku Air-Conditioned Cooling Coat

MCT harnesses infrared radiationsynergistically with the other channels Principle:– Adjustable infrared properties with synergetic control overevaporation and air convectionStrategy:– Meta coupling effect– Moisture/thermally responsive fibersMethod:– Experimental and computationalTargets:– Add 23 W (summer) 18 W (Winter)thermoregulation capacityFigure credit:Dr. Ping Liu, DELTA: Delivering Efficient Local Thermal Amenities,Presented at Delivering Efficient Local Thermal Amenities. DELTAKickoff Meeting, May 21-22, 2015, Portland, ORmeta cooling

Key Parameters of Performanceand Where We Aremeta coolingBaseline ClothingTemperature SetpointLower, 70 oFUpper, 75 oFTotal Thermal Resistance (m2 F/W)0.400.31Updated MCT metrics based on 5th generation thermal modeling (vs. proposed)Temperature SetpointRadiation(m2 F/W)Conduction(m2 F/W)Convection(m2 F/W)Moisture(m2 F/W)Total ThermalResistance(m2 F/W)Expanded Lower, anded Upper, AddedThermoregulationCapacity (W)15.7(20.9)22.1(17.3)Performance targetQ7Q8T equivalent Meta Fiber 0.25 ⁰C 0.5 ⁰CMCT3.12(2.8)Q9 1 ⁰CQ10 1.5 ⁰C 0.5 ⁰CQ11 2 ⁰C 1 ⁰CQ12 2 ⁰C

Key Interim Learning and ResultsTheoretical Model 0.8Temperature Setpoint (K) Finite-difference timedomain modeling ofinfrared opticalproperties.4-layer thermal modelof clothing built withAnsys Fluent.Coupled convection,conduction, radiation,and evaporation (inoffice settings).Emissivity 0.60.40.2Convection110Fiber Spacing ( m) ConductionRadiationMoistureBody AirClothAmbient100 meta cooling302Summer30079298752962947029266 oF290Winter0.20.40.60.81.0Thermally Comfortable Emissivityfor all-season MCTFDTD optical modeling predicts tunableemissivity in the infrared by adjusting thefiber spacing.Numeric thermal model predicts that asetpoint expansion of 4 oF can beachieved by proposed MCT technology.

Key Interim Learning and ResultsDynamic Infrared Response 1st MCT prototypedemonstrates autonomouslytunable infrared emissivity bymore than 10%, adding 1.2oFto thermoregulation capacity.Our data suggest, for the firsttime, that dynamic response inthe infrared can be achievedthrough proposed MCT.meta coolingRH29.8oC30.6oCIR Camera(7.5-14 µm)RH 5%RH 80%MCTT 35oC29.7oCMCT yarnControl RH 5%30.0oCControl RH 80%

Key Interim Learning and ResultsInfrared Measurement System meta coolingSpectrally resolved, quantitative IR measurements of dynamic systems?Environmental chamber integrated FTIR systemTransmittance Reflection Emission– MCT detector covering 1-22 µm or 1-16 µm with microscopeHumidity and temperature controls– Temperature control with 0.1 oC accuracy– Humidity control over 5-95% with a stability of /- 0.5%Newly installed motorized stage for mapping

Summary meta coolingTheoretical optical and thermal modeling predicts a setpointexpansion of 4 oF can be achieved by proposed MCT technology.A proof-of-concept demonstration of proposed MCT has beenestablished through the design of meta fibers and knitted fabric.First prototypical MCT fabric already shows dynamically tunableinfrared properties by more than 10%, adding 1.2 oF to thethermoregulation capacity.The Road Ahead Our project is well on track to deliver a MCT prototype with robustdynamic control over infrared radiation and other main heatexchange channels to achieve bi-directional thermoregulation. Next steps are focused on performance optimization through designfabrication-characterization loops.

How the DELTA Community Can Help?meta cooling1. Markets/Applications/Technology– Finding first applications and first markets2. Experts to connect– Knitting and yarn processing of (fragile) samples on smallerscales.3. Suggestions/opportunities for MCT– Collaborations/Partnerships on product development/MCTtechnology applicationsQuestions? Comments? Suggestions? Please contactYuHuang Wang: yhw@umd.edu

expansion of 4 oFcan be achieved by proposed MCT technology. A proof-of-concept demonstration of proposed MCT has been established through the design of meta fibers and knitted fabric. First prototypical MCT fabric already shows dynamically tunable infrared properties by more