ENGINEERING WORLD HEALTH: COLD BOX GROUP 19 Josh Arenth Cynthia Bien Graham Gipson Elise Springer Brittany Wall

ENGINEERING WORLD HEALTH Organization background:  Founded in 2001  Charitable organization that collaborate with collegiate engineering programs  Improves conditions of hospitals in developing nations  Multi-step process: (1) Assessment of hospitals (2) Ship container of refurbished medical equipment (3) Install equipment and train at location (4) Return to location to reinforce training Engineering World Health: Cold Box (Group 19)

WHY WORK FOR EWH?  Want to improve healthcare in developing countries  Impact the quality of life in developing countries  Give others an opportunity that was given to us Engineering World Health: Cold Box (Group 19)

PROBLEM STATEMENT Build a portable device that:  Keeps a 5-mL fluid volume at 10°C for up to 12 hours,  Operates without electricity or outside fuel,  Can be manufactured for less than $0.20 per unit (500 units for less than $100),  Does not require highly skilled labor to assemble. Engineering World Health: Cold Box (Group 19)

ASSESSMENT  Determine a unique and efficient way to sustain 10°C for 12 hours Will ice work?  CO 2  Freon  Decide which materials are good conductors and which are good insulators  Ultimately determine which materials are both sufficient and cheap, and can be easily produced in the developing world Engineering World Health: Cold Box (Group 19)

Initial Design: Prototype Cold Box Design Specs Outer layer / casing Outer portion of container must be a good insulator (i.e., be an intrinsically poor conductor.) Ideal materials:  Styrofoam  Ceramic  Gas sandwiched between two layers Materials chosen:  Styrofoam with a durable plastic covering Engineering World Health: Cold Box (Group 19)

Initial Design: Prototype Cold Box Design Specs Heat sink Cold Box must have a component to remove heat from box contents Ideal materials:  Non-toxic, non-abrasive chemical reaction  Heat-absorbing material with large heat capacity Materials chosen:  Ice and water  Sodium bicarbonate / acetic acid system Engineering World Health: Cold Box (Group 19)

Initial Design: Prototype Cold Box Design Specs Inner casing Cold Box must have an inner layer to separate the contents of the box from heat-sink materials, yet still allow for efficient heat transfer (i.e., have high conductivity). Ideal materials:  Non-reactive metal  Glass Materials chosen:  Aluminum Engineering World Health: Cold Box (Group 19)

Initial Design: Prototype Cold Box Design Specs Engineering World Health: Cold Box (Group 19) storage cavity heat efflux heat sink heat-conductive inner wall insulating outer wall a + b + Δ → c Schematic description In the cold box, an endothermic chemical reaction (generalized here) consumes thermal energy, thus drawing heat out of the inner cavity. This heat is trapped in the heat sink because of the outer insulating boundary.

PAST WORK  General agreement on twice-weekly, one-hour meetings  Responsibilities assigned to each group member  Took advice from Dr Roselli (BME) to work with an advisor more knowledgeable about chemistry and materials science.  Met with Dr List (Chemistry) and gained his mentorship for our project.  Final version of NCIIA design proposal created and posted on website. Engineering World Health: Cold Box (Group 19)

CURRENT WORK  Each group member has presented their own ideas on how to design the cold box to meet specifications.  Discussion about performing lab experiments for:  Choice of appropriate chemical heat sink  Choice of best insulating / conducting materials  Several experimental set-ups were put on the table Engineering World Health: Cold Box (Group 19)

FUTURE WORK  Members offering different experimental set-ups will generate protocols and a brief rationale statement.  Group will meet with Dr List and seek his opinion of protocols.  Experiments will be performed and first sets of data collected. Engineering World Health: Cold Box (Group 19)