Zensei: Design and longitudinal evaluation of high-speed, wireless, multi-electrode bioimpedance sensing technology for implicit, ubiquitous user recognition. Sato, M., Puri, R., Olwal, A., Ushigome, Y., Franciszkiewicz, L., Raskar, R., Chandra, D., Poupyrev, I. To appear in ACM CHI 2017 [PDF]