More than 3 million people die from vaccine-preventable diseases each year. Approximately 1.5 million of these deaths are in children less than 5 years old, one death almost every 20 seconds. Sadly, many of these deaths are due to failures along the vaccine cold chain in poor and developing countries. Health workers transport vaccines from local health centers to villages on a motorcycle or on foot, carrying a smaller volume container known as a vaccine carrier. The vaccine carriers are filled with ice packs and lack the ability to keep vaccines cold for enough time or the ability to fine-tune the internal temperature. Using novel metal-energy harvesting technology developed by Penn researchers, we invented a vaccine carrier powered by aluminum sheets.