Mycelium-based composites hold significant potential as sustainable alternatives to traditional materials, offering innovative solutions to the escalating challenges of global warming and climate change. This review examines their production techniques, advantages, and limitations, emphasizing their role in addressing pressing environmental and economic concerns. Current applications span various industries, including manufacturing and biomedical fields, where mycelium-based composites demonstrate the capacity to mitigate environmental impact and enhance economic sustainability. Key findings highlight their environmental benefits, economic viability, and versatile applications, showcasing their potential to revolutionize multiple sectors. However, challenges such as consumer acceptance, intrinsic variability, and the need for standardized guidelines persist, underscoring the importance of further research and innovation. By optimizing material properties and refining production processes, mycelium-based composites could pave the way for widespread adoption as sustainable materials, contributing to a greener and more environmentally conscious future.

Graphene, a 2D sp² hybridized carbon sheet consisting of a honeycomb network, is the building block of graphite. Since its discovery in 2004, graphenes exceptional electronic and mechanical properties have peaked interest in various applications. However, the inability to mass produce high-quality graphene affordably currently limits the practical application of the material. Researchers are continuously working on advancing graphene synthesis methods to alleviate these limitations. Therefore, this review looks at the overview of established graphene synthesis methods and characterization techniques, and then highlights an in-depth review of graphene production through flash joule heating. The environmental concerns related to graphene synthesis are also presented in this review paper.

As the global interest in renewable energy generation continues, the need to develop new and innovative solutions is being explored every day throughout the world by researchers and innovators. Hybrid renewable energy innovations are gaining progressive interest not only because of the threat of climate change but also due to the technological advancements seen in renewables. Ocean waves have immense potential as a renewable energy source, and related technologies have advanced continuously over the past few decades. In response, this paper extensively studies wave energy converters (WECs) based on the power take-off (PTO) technique, and presents a novel hybrid wave-plus-photon energy (HWPE) harvester called Wavevoltaics, based on wave and solar energy capture systems for coastal communities’ power needs, in line with decarbonization measures. The HWPE harvester uses a simple rack-and-pinion mechanism in combination with solar cell technology to convert the wave energy into usable electrical energy in a water column structural design. This novel HWPE device can be used to provide power for lighting and gadgets for coastal communities that rely heavily on fossil fuels for their lighting and electrical needs. Later in the paper, the challenges faced in hybrid wave energy development are presented.

Recently, energy harvesting through human locomotion has emerged as a promising source of clean energy for fueling low-power smart electronic devices. As energy plays a pivoted role in all sectors, the prospect of harnessing clean energy from human footsteps has become a focal point in the quest for sustainable energy solutions. This article presents a comprehensive exploration of various kinetic energy harvesting technologies—such as piezoelectric, rack and pinion, triboelectric nanogenerators, human mounted, Pavegen, airflow-based, and fluid-flow based energy harvesting systems that are being employed to produce biomechanical energy from simple human motion. The systems require small displacements such as walking and movement of human limbs. The discussion explores the complexity of design, operating principles, and performance evaluations of these cutting-edge human motion energy harvesters. Furthermore, the article delves into a critical assessment of the limitations, benefits, and challenges confronting piezoelectric and electromagnetic energy harvesting technologies in the realm of low-power practical applications. The review indicates that piezoelectric flooring systems, rack and pinion harvesters, triboelectric nanogenerators and wave spring generators hold great promise for footstep energy harvesting. With improvements in piezoelectric materials, it is expected that the efficiency of footstep energy harvesters will improve and with the ongoing reduction in the power requirements of portable devices, they will be able to serve as a clean and mobile source of energy for such devices.

As fossil fuels near depletion and their detrimental side effects become prominent on ecosystems, the world searches renewable sources of energy. Marine current energy is an emerging and promising renewable energy resource. Marine current energy can be alternative energy source for electricity production. Many marine current converters are designed to tap marine current energy; however, Gorlov turbine proves to have minimum manufacturing and maintenance cost, hence giving desired power output. A 0.3m diameter and 0.6m long 3 bladed Gorlov turbine was designed, fabricated and test to analyse its performance. The turbine produces average power 15 W and proves to be quite efficient for marine current energy extraction.

Amongst all the energy sources from human motion, footstep has the potential of producing electrical energy as an alternative source to non-conventional renewable energy. Researchers have shown that human footstep kinetic energy can be converted to electrical energy by devised mechanism for low power application such as powering lights, radio and charging phones. Eventually, a novel fluid based energy harvesting paver was developed and tested to contribute towards sustainable development. The paver uses mini hydro generators to produce energy as fluid is forced through these mini hydro generators upon human stepping. This paper presents the pressure simulation of fluid bag system when subjected to an applied human force and the quarter ellipsoid shaped proved to be the best performer which can produce upto 1.4J per step. The pressure simulation provides a relation between pressure and output power.