![](https://www.popsci.com/wp-content/uploads/2019/03/18/SPO4WJ4JRAGHTBTK3FDKTT4CKE.jpg?w=1200)
![](https://www.popsci.com/wp-content/uploads/2019/03/18/SPO4WJ4JRAGHTBTK3FDKTT4CKE.jpg?w=1200)
When a couple can’t conceive, in-vitro fertilization (IVF) may help. But the hefty price tag limits its use to rich countries; it also suggests growing an egg outside the womb requires high-tech equipment. The Walking Egg Lab achieves the right incubation pH and temperature with just a basic cooler containing vials of citric acid and bicarbonate, cutting the cost of IVF by a factor of five to ten.