Effects of Foam Type and Thickness on Impact Resistance, Thermal Insulation, and Cost-Effectiveness of Medical Containers for Drone Delivery

Accessible healthcare remains a challenge for rural communities lacking reliable infrastructure for medical supply delivery. Delivery drones have recently emerged as a viable alternative, dropping medical containers during flight. However, the effectiveness of different foam types and thicknesses combined with corrugated cardboard as shock-absorbing materials in a medical container for delivery drones has yet to be tested. Thus, this study designed cost-effective containers using corrugated cardboard and multiple foam types and thicknesses, aiming to preserve the integrity of the contents, withstand impact, and control temperatures. Four foam types—polystyrene, polyurethane, polyethylene, and expanded polystyrene (EPS) —were tested at 1 cm, 2 cm, and 3 cm thicknesses using a 4x3 experimental factorial and between-groups research design. Temperature insulation was assessed by recording internal temperatures every minute for 1 hour across three trials, aiming to maintain the ideal range of 2–6 oC. Impact resistance was tested by dropping each container from a height of 16.82 meters three times, and the integrity of the medical contents was checked after each drop. The cost-effectiveness of each container was evaluated using a descriptive ranking approach. All containers protected their contents after multiple drops; however, only containers with a 3 cm thickness, regardless of foam type, and 2 cm-thick EPS foam consistently maintained the ideal temperature range. Considering both performance and price, a 3 cm-thick polyethylene foam container emerged as the most cost-effective design. Future studies should include quantitative analysis of shock absorption and vibration using appropriate sensors, and can test additional foam types and thicknesses.