The Z machine is located in Albuquerque, N.M., and is part of the Pulsed Power Program, which started at Sandia National Randy Montoya/Sandia National Laboratory hide caption

itoggle caption Randy Montoya/Sandia National Laboratory

Current water-filtering technology is costly, but MIT scientists are testing a simpler and cheaper method that uses wood from white pine trees. Wikimedia Commons hide caption

itoggle caption Wikimedia Commons

About 50,000 years ago, a meteorite struck earth east of present-day Flagstaff, leaving this crater as its calling card. Shane.torgerson/Wikimedia Commons hide caption

itoggle caption Shane.torgerson/Wikimedia Commons

A nurse attaches the low-cost breathing machine (far left) to an infant at The Queen Elizabeth Central Hospital in Blantyre, Malawi. Jocelyn Brown/Rice University hide caption

itoggle caption Jocelyn Brown/Rice University

Neonatal nurse Florence Mwenifumbo monitors a newborn receiving bubble CPAP treatment in Blantyre, Malawi. The device was developed by students at Rice University in Houston. Rice 360/Rice University hide caption

itoggle caption Rice 360/Rice University

Dee Faught tests a robotic arm installed on his wheelchair in September. Commercially produced robotic arms can cost tens of thousands of dollars, but three Rice engineering students built one for Dee for about $800. Eric Kayne for NPR hide caption

itoggle caption Eric Kayne for NPR