Designing Energy Harvesting Skin Structure Utilizing Outdoor Unit Vibration

Abstract

This paper presents a new energy harvesting (EH) concept design, referred to as EH skin structure. A generic design and experimental verification methodology will be proposed to demonstrate the feasibility of the EH skin for practical applications. In the past, EH researches have primarily focused on designing a device-level energy harvester, such as a cantilever-type EH device. However, such a device-level energy harvester has several drawbacks: (i) need of an extra space for proof masses and fixture, (ii) significant energy loss due to the fixture, and (iii) need of a casing for EH device protection against environmental harms. While this new EH concept design could overcome the drawbacks above, there is no design methodology for EH skin. This paper proposes design and experimental verification methodology for EH skin structure. The design methodology comprises three tasks: (i) construction of a valid computational model, (ii) design optimization of EH skin, and (iii) experimental verification. An outdoor condensing unit of which a fan produces harmonic vibration is chosen for a case study because similar configuration of vibration can be found in many engineered systems (e.g., airplane wing, AC unit). The proposed design methodology determined an optimal EH skin configuration (sizes, locations, etc.) on the vibrating structure. The EH skin was carefully prototyped to demonstrate that it can generate power up to 3.7mW, which is sustainable for operating wireless sensor units for structural health monitoring or building automation.