A single-material multi-source energy harvester, multifunctional sensor, and integrated harvester-sensor system-demonstration of concept

Abstract Single‐source energy harvesters that convert solar, thermal, or kinetic energy into electricity for small‐scale smart electronic devices and wireless sensor networks have been under development for decades. When an individual energy source is insufficient for the required electricity generation, multi‐source energy harvesting is indicated. Current technology usually combines different individual harvesters to achieve the capability of harvesting multiple energy sources simultaneously. However, this increases the overall size of the multi‐source harvester, but in microelectronics miniaturization is a critical consideration. Herein, an advanced approach is demonstrated to solve this issue. A single‐material energy harvesting/sensing device is fabricated using a (K0.5Na0.5)NbO3‐Ba(Ni0.5Nb0.5)O3–Δ (KNBNNO) ceramic as the sole energy‐conversion component. This single‐material component is able simultaneously to harvest or sense solar (visible light), thermal (temperature fluctuation), and kinetic (vibration) energy sources by incorporating its photovoltaic, pyroelectric, and piezoelectric effects, respectively. The interactions between different energy conversion effects, e.g., the influence of dynamic behavior on the photovoltaic effect and alternating current–direct current (AC–DC) signal trade‐offs, are assessed and discussed. This research is expected to stimulate energy‐efficient design of electronic devices by integrating both harvesting and sensing functions in the same material/component

Investigation of a cantilever structured piezoelectric energy harvester used for wearable devices with random vibration input

Abstract The capability of using a linear kinetic energy harvester — A cantilever structured piezoelectric energy harvester — to harvest human motions in the real-life activities is investigated. The whole loop of the design, simulation, fabrication and test of the energy harvester is presented. With the smart wristband/watch sized energy harvester, a root mean square of the output power of 50 μW is obtained from the real-life hand-arm motion in human’s daily life. Such a power is enough to make some low power consumption sensors to be self-powered. This paper provides a good and reliable comparison to those with nonlinear structures. It also helps the designers to consider whether to choose a nonlinear structure or not in a particular energy harvester based on different application scenarios

A game changer:a multifunctional perovskite exhibiting giant ferroelectricity and narrow bandgap with potential application in a truly monolithic multienergy harvester or sensor

Abstract An ABO3-type perovskite solid-solution, (K₀.₅Na₀.₅)NbO₃ (KNN) doped with 2 mol% Ba(Ni₀.₅Nb₀.₅)O₃−δ (BNNO) is reported. Such a composition yields a much narrower bandgap (≈1.6 eV) compared to the parental composition—pure KNN—and other widely used piezoelectric and pyroelectric materials (e.g., Pb(Zr,Ti)O₃, BaTiO₃). Meanwhile, it exhibits the same large piezoelectric coefficient as that of KNN (≈100 pC N⁻¹) and a much larger pyroelectric coefficient (≈130 µC m⁻² K⁻¹) compared to the previously reported narrow-bandgap material (KNbO₃)₁₋ₓ-BNNOₓ. The unique combination of these excellent ferroelectric and optical properties opens the door to the development of multisource energy harvesting or multifunctional sensing devices for the simultaneous and efficient conversion of solar, thermal, and kinetic energies into electricity in a single material. Individual and comprehensive characterizations of the optical, ferroelectric, piezoelectric, pyroelectric, and photovoltaic properties are investigated with single and coexisting energy sources. No degrading interaction between ferroelectric and photovoltaic behaviors is observed. This composition may fundamentally change the working principles of state-of-the-art hybrid energy harvesters and sensors, and thus significantly increases the unit-volume energy conversion efficiency and reliability of energy harvesters in ambient environments