A System of Wearable Electronic Heaters to Provide Bodily

Temperature Control

Wednesday, December 7th, 2016MEEN 475 - 502Samuel Terrill | Matthew Pledger | Andres Barrios | Richard Meeks | Guillermo Villalobos | Kyle SlatonInstructor: Dr. Tanil Ozkan

Outline

Market Need

System Overview

Material Selection

Material Process Selection

Auxiliary Part Selection

Conclusions

Introduce system background

•For athletes, every training session is essential to improve performance•Missed practices due to cold temperatures can hinder athletic growth•These athletic bands were thus created in order to heat up athletes during winter workouts to prevent unnecessary expenditure of energy

System OverviewThin bands of silicone rubber with copper wiring embedded circumferentially.

Contains a thin battery, small microcontroller, and temperature sensor

Bands are scalable for warming critical areas of the human body-near wrists, upper arm, legs, abdomen

Added benefit of keeping muscles warm for injury prevention.

Merit Index Derivation – Resistance Heater

Ashby Charts

● Young’s Modulus must remain below 150 GPA.

● Electrical resistivity must be minimized.

● Thermal conductivity greater than 100

AHP

Ranking: Thermal conductivity (K) = 2, Elastic Modulus (E) = 3,

Thermal Resistivity (𝜌e ) = 4, Density ( ) = 5, Cost (C) = 6𝜌Material Score Rank

Copper 0.49323 1

Aluminium 0.24353 3

Zinc 0.26325 2

Manufacturing Process

Final Selection: Sheet Forming Final Selection: Injection Molding

Temperature Sensor

Made of graphite and semi-crystalline acrylate polymer formed by 2 monomers

Flexible

Lightweight

Printable

Accurate "A Printable, Flexible, Lightweight Temperature Sensor." Phys.org - News and Articles on Science and Technology. N.p., 9 Nov. 2015. Web. 03 Dec. 2016.

Insulation

For insulation, material selection was qualitative

Desire higher resistivity for shock prevention

Desire medium thermal conductivity for mild insulation but adequate transfer to person

Thermodynamic Analysis[1] Qin,Device = Wout,activity + Qout,activity + Qout,body

[2] Qout,activity + Wout,activity = Metabolic Equivalent of Task (MET)[3] MET = METs × 3.5 × mass ÷

200[4] Qout,body = 100 Wh

→Qin,device = 365.468 kJ

Power Source

● Selected CP9V as power source.

● Slightly more expensive than others, but reasonable in bulk.

● Supports the required power as calculated.

Conclusions

Target Market: Athletes and Outdoor Enthusiasts

Design: Thin, circular, silicone bands with wiring

Components: Thin battery, temperature sensor, and small microcontroller

Merit Indices:

Ashby method and industry research nominated silicone rubber for the bands

AHP Method nominated copper as final product for electrical wiring

Questions?

Referenceshttp://www.matweb.com/search/datasheet.aspx?matguid=9aebe83845c04c1db5126fada6f76f7e&ckck=1http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA6063T1http://www.matweb.com/search/DataSheet.aspx?MatGUID=8909140a76074049809ad74d536ed606&ckck=1http://www.infomine.com/investment/metal-prices/http://www.boatzincs.com/zinc-vs-aluminum-chart.htmlhttp://www.brightvolt.com/products/flexion-batteries/http://jap.physiology.org/content/87/5/1957.full#sec-18http://phys.org/news/2015-11-printable-flexible-lightweight-temperature-sensor.htmlhttps://www.shinetsusilicone-global.com/catalog/pdf/rubber_e.pdfhttp://www.azom.com/properties.aspx?ArticleID=920http://www.eurotherm.com/products/power-control/zelio-solid-state-relays/i-o-series-output