So, what are battery-free sensors?
The devices collect, process, and transmit data without relying on traditional power sources like batteries. The sensors are utilising innovative energy harvesting techniques to extract power from the surrounding environment, enabling them to operate autonomously for an extended period of time.
Battery-free sensors do not rely on disposable or rechargeable batteries but leverage various sources of ambient energy such as light, heat, vibrations, or radio waves for their operation. The several key components of battery-free sensors are:
- Capturing and converting the incorporated energy harvesting mechanisms for ambient energy into electrical power The mechanisms can be based on photovoltaic cells, which convert light energy into electricity, and thermoelectric generators, which utilize temperature differences as piezoelectric materials to convert mechanical vibrations into electric power for harnessing electromagnetic waves.
- Low-power electronics and circuitry are employed to minimise energy consumption. The components are designed to operate efficiently with minimal power requirements, allowing the harvested energy to be used optimally.
- Radiofrequency identification (RFID) wireless communication technology is integrated into battery-free sensors. It enables transmitting data wirelessly to other devices or systems, eliminating the need for wired connections.
In various domains, battery-free sensors find benefits in such applications as healthcare, environmental monitoring, smart infrastructure, agriculture, and more. Various advantages are offered, such as reduced maintenance needs, extended operational lifetimes, and the ability to deploy a large number of sensors in remote or inaccessible locations.
In recent times, battery-free sensors have emerged as a promising technology to enable the collection and transmission of data without the need for traditional power sources.
In the healthcare sector, sensors are used for remote patient monitoring, tracking vital signs, and drug delivery systems. Battery-free sensors are deployed in large numbers for monitoring air quality, water pollution, temperature, and humidity. The sensors are also cost-effective solutions for gathering environmental data in remote areas or inaccessible locations.
Smart infrastructure and building automation are also major beneficiaries of battery-free sensor technology. The sensors can detect structural changes, vibrations, and strain, enabling proactive maintenance and enhancing safety.
In the agricultural sector, soil moisture sensors are also powered by solar energy and can monitor moisture levels and provide data for optimised irrigation, resulting in water conservation and improved crop yield.
But battery-free sensors are not without challenges. They often face problems in terms of range and data transmission speed due to their low-power nature. The efficiency of energy harvesting is improved by optimising the communication protocols and developing more sophisticated data compression techniques to address the challenges.
The scalability and cost-effectiveness of battery-free sensors also need to be considered.
Source: Nature communications, marketsandmarkets, onsemi