Telegraph: The process of adding thin layers of material on top of each other to create a final product has been adapted for use with human embryonic stem cells (hESCs). Will Shu of Heriot-Watt University in Edinburgh and his colleagues created an adjustable microvalve that allowed them to produce clusters of hESCs. Shu says that the process is gentle enough that it doesn’t destroy the cells or cause them to lose their ability to differentiate into other types of cells, and it is accurate enough to create a variety of sizes of spheroids. The technology could be used to incorporate stem cells into transplant-ready lab-grown organs and tissues. By using stem cells cloned from the patient, the transplant should avoid triggering a dangerous immune system response. The technique could also be used to create tissues and organs for pharmaceutical testing.