G Love

Kristin BrodieJeff Colton

Colin GalbraithBushra MakiyaTiffany Santos

Fabrication of Microspheres

Used protocol learned at beginning of semester to fabricate PLGA microspheres

Homogenizer speed: Paraffin: 3.5, 5 Octadecane: 4, 5

Pipette used to separate water and paraffin

Filter used for octadecane (0.22m)

SEM of Microspheres

Paraffin Wax Homogenizer speed

5 Average size:

150m Range: 50 – 300m

SEM of Microspheres (2)

Paraffin Wax Homogenizer speed

3.5 Average size: 200m Range: 50 – 400m

DSC for Octadecane and PEG

Octadecane PEG

Heat Flow Model for a Finger Finger assumed to be a cylinder Power = 2rLq = 2L(T1-T3)/R

R = Fabric Resistance + BL Resistance FR = 1/kc * ln (rc/rw) BLR = 1/(rc*h)

h = 1.22*(T/D)^(1/4) for a horizontal pipe Approximating values:

h~10 W/m2K Power~2.5 W

A hand can be assumed to be a cylinder rhand = 2*rfinger

Heat Transfer Through Gloves

Heating element in the glove (73cm)

Thermistor in and out of the glove

Power: 3.6V Current: 0.55A Weight to reduce air

flow into glove

Heat Flow Results

I*V/A = h (T[in] – T[out]) I = 0.55A V = 3.6V A = 0.05m2

T[in] = 317.42K T[out] = 294.98K

h = 1.765 W/m2K

Event

T [in] T [out]

1 109.9 71.5

2 112.4 71.9

3 112.6 71.6

4 112.5 71.1

5 112.2 71.6

6 112.1 71.7

Avg 111.95

71.57

Data for Heating Element Wires

Ni:Cr 80:20wt%

Ni:Cr:Fe 60:16:24 wt%

Stainless Steel Fe:Cr:Ni 70:19:11 wt%

Starting Diameter (mm)

0.41 0.40 0.375

Area of Wire (in2) 0.00807 1.192e-4 1.7e-4

Suggested Stress (kpsi)

120 74-130 ~95

Length of Graph (in) 19.5 21.7 35

Extension (in) 1.95 2.17 3.5

Max Load (lbs) 24.2 21 17.5

Calculated Stress (kpsi)

121 107.8 102.2

Curve for Ni:Cr 80:20wt%

Ni:Cr 80:20wt%

0

5

10

15

20

25

30

1 3 5 7 9 11 13 15 17 19 21 23 25 27

Distance (inch)

Lo

ad

(lb

s.)

Results Ni:Cr 80:20wt% chosen for large elastic

region Octadecane preferred over PEG for Heat

of crystallization properties Experimental thermal coefficient is

similar to theoretical value

What Will We Do Next? Phase Change Material

Test integrity of PVA Fabricate microspheres of PEG Incorporation of phase change material into fabric DSC of microspheres

Heating Elements Test battery with Prof Ceder Incorporation of thermal switch Choose a fabric to get specific thermal properties