Monique Yusizanna Ouz, 66, is going to have electricity for the first time in her life. Carrie Kahn/NPR hide caption

itoggle caption Carrie Kahn/NPR

The sun sets as a visitor uses his mobile phone Monday during the opening day of the 2015 Mobile World Congress in Barcelona. Wall Street Journal reporter Ryan Knutson — interviewed from the conference Monday via Skype by NPR's Robert Siegel — says that for some smartphone users, Wi-Fi may be able to replace most of the functionality of a cellphone carrier. Josep Lago/AFP/Getty Images hide caption

itoggle caption Josep Lago/AFP/Getty Images

Randall Stephenson, chairman and CEO of AT&T, introduces President Obama before the latter's remarks Dec. 3 at the quarterly meeting of the Business Roundtable, a group Stephenson chairs. Stephenson has said that increasing regulation of the broadband industry — as proposed by the president — would have a substantial chilling effect on its investment in infrastructure. Pool/Getty Images hide caption

itoggle caption Pool/Getty Images

David Goldhill (second from left) talks with Dan Hilferty of Independence Blue Cross, Kevin Nazemi of Oscar Insurance and Sam Nussbaum of WellPoint in a conversation about health costs. Moderator Avik Roy is at far left. Glen Davis/Forbes hide caption

itoggle caption Glen Davis/Forbes

Students taking part in Columbia University's Ebola design challenge demonstrated for judges how to use a special chamber for decontaminating small items. Courtesy of Columbia Engineering hide caption

itoggle caption Courtesy of Columbia Engineering

Solar sponge: The top layer of graphite soaks up the sun's energy in tiny holes. When drops of liquid fill the holes, the water quickly evaporates. (The beaker looks hot, but the water below the sponge is cool as a cucumber.) Courtesy of George Ni/MIT hide caption

itoggle caption Courtesy of George Ni/MIT

All folded up and ready to magnify: The Foldscope weighs less than two nickels, is small enough to fit in your back pocket and offers more than 2,000-fold magnification. TED/YouTube hide caption

itoggle caption TED/YouTube

Clear and clean, bubble wrap is well-suited to serve as an array of tiny test tubes. Here a dye solution is injected into the bubbles to measure the hemoglobin concentration in blood. American Chemical Society hide caption

itoggle caption American Chemical Society

The Liftware device, shown here as an early prototype (left) and the final design, starts up automatically when it's lifted from the table. There's no "on" switch to fumble with. Ina Jaffe/NPR hide caption

itoggle caption Ina Jaffe/NPR

Revelers play Johann Sebastian Joust. Brent Knepper/Courtesy of jsjoust.com hide caption

itoggle caption Brent Knepper/Courtesy of jsjoust.com

Elizabeth, Samuel, Bryan and Noah Shaw amid Texas bluebonnets on Easter Sunday. Samuel was conceived with in vitro fertilization so he would not suffer from the hereditary cancer that afflicted Noah. Courtesy of Elizabeth Shaw hide caption

itoggle caption Courtesy of Elizabeth Shaw