# Fluid Flow-Based Vibration Energy Harvesters: A Critical Review of State-of-the-Art Technologies
## 9 Discussion, Future Prospects and Challenges for FBEHs
Despite significant advances and promising results in laboratories, the practical application of flow energy harvesting devices has encountered various challenges. The intricate nature of fluid dynamics and the variety of flow conditions in real environments are two of the key reasons why implementation has not kept pace with lab research. Flow energy harvesting systems rely primarily on the velocity and direction of the flow, which can vary drastically in real natural environments. As a result, maintaining the reliable and continuous generation of power from fluctuating flows remains a significant challenge that needs to be overcome in future. The key areas to be addressed in the field of flow-induced energy harvesting are to improve the efficiency, reliability and durability of FBEHs in harsh environments for long durations and increase the power density. This can be achieved by developing novel designs and advanced materials for FBEHs that are more efficient and inexpensive. As FBEH technology matures, it is projected to have a substantial impact on a variety of areas and applications. Some rotary wind energy harvesters (typically EM) are designed to harvest energy from several axes, allowing them to harvest wind energy with both rotational motion and induced vibrational motion along longitudinal, transverse or vertical directions. This feature broadens the range of potential energy sources that can be utilized. However, these solutions are only implemented and tested in a controlled laboratory environment, which may not accurately represent the complex and dynamic conditions of the real world. Additionally, when energy is harvested, the power management circuit relies on various components, each of which requires power drawn from the harvester. In systems operating in variable wind conditions, efficiently distributing power to all components becomes particularly challenging, especially in compact designs where space and resources are limited. Furthermore, power circuits in remote regions are highly susceptible to failure due to harsh environmental conditions, inadequate infrastructure and the risk of physical damage. These factors can cause significant disruptions in the energy supply, complicating the reliable operation of the system. To address the aforementioned problems, researchers should prioritize field testing and validation of FEEs in diverse and actual environments. Collaborations with industry partners can help to gain access to relevant testing grounds, ensuring that energy harvesters are resilient and effective under a variety of scenarios. Moreover, collaboration between academics and industry via establishing interdisciplinary research teams should be encouraged. By merging expertise in structural dynamics, flow-induced phenomena, power management and wireless sensing, these teams can develop innovative solutions that address complex challenges. Creating collaborative research initiatives and industry-academic alliances and encouraging individuals with various experiences to collaborate can result in a more holistic approach to solving difficulties and producing comprehensive solutions.