Digital Pregnancy Test Powered by an Air-Breathing Paper-Based Microfluidic Fuel Cell Stack Using Human Urine as Fuel oleh Irma Lucia Vera-Estrada, Juan Manuel Olivares-Ramírez, Juvenal Rodríguez-Reséndiz, Andrés Dector, Jorge Domingo Mendiola-Santibañez, Diana María Amaya-Cruz, Adrían Sosa-Domínguez, David Ortega-Díaz, Diana Dector, Victor Manuel Ovando-Medina, Iveth Dalila Antonio-Carmona