Towards wearable piezoelectric energy harvesting: modeling and experimental validation

Abstract

Motion energy harvesting is an ideal alternative to battery in wearable applications since it can produce energy on demand. So far, widespread use of this technology has been hindered by bulky, inflexible and impractical designs. New flexible piezoelectric materials enable comfortable use of this technology. However, the energy harvesting potential of this approach has not been thoroughly investigated to date. This paper presents a novel mathematical model for estimating the energy that can be harvested from joint movements on the human body. The proposed model is validated using two different piezoelectric materials attached on a 3D model of the human knee. To the best of our knowledge, this is the first study that combines analytical modeling and experimental validation for joint movements. Thorough experimental evaluations show that 1) users can generate on average 13 μW power while walking, 2) we can predict the generated power with 4.8% modeling error.