The significance of flexible sensors has been extremely significant in the case of energy-harvesting applications. Flexile sensors with varied electromechanical properties have been utilized for piezoelectric, triboelectric and pyroelectric-sensing applications. This chapter concludes the research work explained in the preceding chapters by highlighting some of the essential characteristics of the flexible sensors. The chapter also elucidates the future opportunities of flexible sensors for real-time energy-harvesting and other related applications. It explains some of the possible steps that can be followed to enhance the quality of these sensors so that they can be commercialized and used as point-of-care devices. The availability of the raw materials that are being processed to form the three types of energy-harvesting devices has been showcased with an estimation of their future trend in the next few years.