Handwritten LEDs Light Up the Page

Abstract

E ven in our digital age, ballpoint pens are an irreplaceable tool for writing down flashes of inspiration or signing legally binding documents. The ink flowing through these everyday objects has always been a passive absorber of light, but Junyi Zhao fromWashington University in St. Louis and colleagues have now changed that [1]. The team has designed a ballpoint pen that writes with ink that produces light as a light emitting diode (LED).