Scalable indoor power harvesters using halide perovskites

Buildings are the largest consumers of primary energy; consuming ~30% of it and also the building sector accounts for ~28% of total CO2 emissions globally. Recent studies have shown that by incorporating smart technologies such as the Internet of Things (IoT) into the buildings' energy system, energy savings of up to ~45 % are possible. IoT refers to a smart network of internet-connected everyday electrical and electronic devices which can communicate with each other and respond rapidly in real time. IoT-incorporated smart buildings have the promising potential to save our limited energy supply and reduce the waste of resources, money and time by continuously monitoring the different processes in buildings and optimising energy use. A smart building will utilise innumerable wireless sensors such as occupancy, humidity, temperature, proximity etc to monitor different processes and energy consumption.

The latest market analysis (McKinsey & Company 2021) has shown that by 2030, the economic potential of IoT would range from $5.5 to 12.6 trillion and there would be more than 1 trillion connected devices. More than half of these devices and one-third of the economic value potential are expected to come from 'indoor' settings. How are we going to power these billions of connected devices? Connecting these sensor devices to the electrical grid is unfeasible as it requires extensive and complex installation and wiring, restructuring of the buildings, and limits the sensors' portable deployability across the buildings. The use of batteries is not sustainable as the limited lifespan of the batteries brings service interruptions during a battery replacement, increases maintenance costs, and poses severe environmental issues at their disposal. Moreover, once IoT has reached its projected wireless sensor nodes of one trillion, millions of battery replacements would be required per day which is unsustainable and impractical. My proposed research will bring a practical solution to this by developing inexpensive and environmentally friendly power sources by harvesting the freely available energy inside the buildings such as light from artificial light sources, heat energy and mechanical energy from electrical appliances which are otherwise lost as a wasted form of energy.

For this, I will tune the properties of a family of electronic materials called 'hybrid perovskites'. The two physical properties that I envisage exploiting for this 'multiple' energy harvesting are (a) photovoltaic - converting light to electricity and (b) piezoelectricity - converting mechanical vibrations to electricity. The hybrid energy harvesters that I develop will make the IoT technology more sustainable by reducing their sole dependence on batteries, and accelerate the wide acceptance of IoT in other applications such as in complete digitisation of manufacturing (industry 4.0), health care, agriculture, precision farming, smart city and transportation settings. In addition to the IoT, the hybrid harvesters that I develop will make other emerging technologies such as Wearables more sustainable and the associated data collection, especially related to health monitoring, more reliable.