Fiber Bragg grating-based sensor for torque and angle measurement in a series elastic actuator’s spring - Sanchez, Manuel R. A.; Leal-Junior, Arnaldo; Segatto, Marcelo V.; Marques, Carlos; Santos, Wilian Miranda dos; Siqueira, Adriano Almeida Gonçalves; Frizera Neto, Anselmo (Applied Optics, 2018)