Floor Tile Energy Harvester for Self-Powered Wireless Occupancy Sensing

Abstract

We investigate a concept that can reduce the overall power requirement of a smart building through improvements in the real-time control of HVAC and indoor lighting based on the building occupancy. The increased number of embedded sensors necessary to realize the smart building concept results in a complex wiring and power structure. We demonstrate a floor tile energy harvester for creating a wireless and self-powered occupancy sensor. This sensor termed as "Smart Tile Energy Production Technology (STEP Tech)" can be used to control automation in smart buildings such as lighting and climate control based upon the real-time building occupancy mapping. The sensor comprises of piezoelectric transducer, energy harvesting circuit and wireless communication. Modeling and optimization procedure for the piezoelectric cymbal transducer is described within the framework of tiles. The design and selection of a packaging technique and construction of a durable floor tile enclosure aimed at protecting the bulk piezoceramic is discussed within the constraint that the deflection of the tile should be minimal such that it is not readily perceivable by humans, thus not disturbing their gait. Experimental results demonstrate that the piezoelectric tile could provide a promising solution for wireless occupancy sensing.

Energy harvesting with piezoelectric materials for IoT – Review

“…If it is used a large number of transducers, the more potential there is for energy to be harvested before the transducers become overloaded, but it decreases the sensitivity of the tile, or the amount of energy produced per load. Therefore, it is an optimum number of transducers to be employed for maximum energy harvesting from a target weight [4]. Sharpes et al [4] have found that for a child (32 kg) the optimum number of transducers is 4, for an average adult (82 kg) is 8 transducers and for a 115 kg adult, the optimum number is 14 transducers.…”

“…Therefore, it is an optimum number of transducers to be employed for maximum energy harvesting from a target weight [4]. Sharpes et al [4] have found that for a child (32 kg) the optimum number of transducers is 4, for an average adult (82 kg) is 8 transducers and for a 115 kg adult, the optimum number is 14 transducers. However, a tile optimized for a child can make more energy per step at low weights, but has a much lower maximum possible energy production compared to a tile optimized for an adult [4].…”

“…Sharpes et al [4] have found that for a child (32 kg) the optimum number of transducers is 4, for an average adult (82 kg) is 8 transducers and for a 115 kg adult, the optimum number is 14 transducers. However, a tile optimized for a child can make more energy per step at low weights, but has a much lower maximum possible energy production compared to a tile optimized for an adult [4]. Another observation in their article is that after a certain minimum weight, the floor tile will produce a constant amount of energy per step, regardless of the load [4].…”

“…In this decade, energy consumption in the USA has risen to more than quadrillion BTU (British Thermal Unit) per year, with around 41% of this energy consumption coming from buildings in the residential and commercial sectors [4]. So, smart buildings and clean energy harvesting became a necessity in our days.…”

Powering Lights with Piezoelectric Energy‐Harvesting Floors

“…Investigations on energy‐harvesting floors have been conducted by researchers from academia and companies. Sharpes designed a tile based on PZT cymbal transducers capable of powering wireless signal transmissions, and Bischur proposed using PVDF‐based modules . Notable efforts have been conducted in developing electromagnetic energy‐harvesting tiles .…”