Wearable electronic devices are becoming increasingly smaller and more complex. As a result, it has become challenging to provide them with sufficient energy. In a recent review, Pusan National University scientists take stock of the latest developments in energy harvesting and storage technology for wearable devices, with a focus on nanomaterials and their assembly into various macroscale structures. Their work aims to accelerate the design of wearable technology and shape their future demands.
Wearable electronic devices have evolved a lot in recent years, unlocking novel applications in healthcare, fitness monitoring, data collection, communication, and more. However, the natural progression towards smaller, lighter, more complex, and multifunctional wearables has also made it more challenging to provide these devices with suitable energy sources. Fortunately, research is being conducted on different methods to meet the energy demands of next-generation wearable devices.
In particular, nanoscale materials, if assembled into appropriate macroscale structures, can not only provide the flexibility that wearables need but also harvest and store the necessary energy for operation through various mechanisms. In a recent paper published in Advanced Functional Materials, an international research team reviewed the latest progress in energy harvesting and energy storage for wearable devices using structured nanomaterials. The team included Assistant Professor Ha Beom Lee of Pusan National University, Professor Seung Hwan Ko of Seoul National University, and Dr. Hyun Kim of Korea Research Institute of Chemical Technology in Korea.
There are many different ways to harvest energy in wearable devices and convert it to electricity. Some of the most promising mechanisms include biomechanical energy harvesters, which gather energy from the natural motions of the human body, biothermal energy harvesters, which produce electricity from body heat, and wearable solar cells. The article also delves into energy storage technologies, such as wearable batteries and supercapacitors, and hybrid devices, which combine multiple forms of energy harvesting and/or storage in a single package.
In particular, the review focuses on how different types of nanomaterials can be used in 1D, 2D, and 3D structures and configurations for energy harvesting and storage, outlining the main advantages and limitations of each. “Our comprehensive overview on nanomaterials and their properties, advanced processes, optimized structural design, and integration strategies for energy devices will contribute to the practical deployment of power systems that can be used in wearables in the near future,” remarks Dr. Lee.
Overall, this work should help shape the future demand for self-sustainable wearable devices, which will include smartphones, watches, glasses, tattoos, textiles, e-skin sensors, and healthcare devices. Dr. Lee concludes by highlighting important research directions to accelerate the development of wearable technology: “Further studies should focus on refining nanoscale materials, structures, and interfaces, develop appropriate macroscale device configurations tailored for specific applications, and propose integration strategies to synergistically combine multiple energy harvesting and storage units to achieve reliable operation.”
Hopefully, the review article will help researchers become updated and inspire new ideas, speeding up the development of wearable electronics and, eventually, their integration into our daily lives.