Maintenance-Free IoT Networks Inspired by Nature

With tens of billions of Internet of Things (IoT) devices deployed globally, this revolution has officially come of age, transforming industries and changing the way we live and work, with applications ranging from smart cities and industrial automation to healthcare and environmental monitoring. But as the number of IoT devices in the wild continues to grow, and sensor networks get larger and cover bigger geographical areas, issues are beginning to arise.

In particular, maintaining devices in the field is proving to be very labor-intensive and expensive. One of the primary reasons for these problems is wireless communication. It is essential for most IoT applications — the collected data is not of much use unless it can be retrieved — yet it also draws a lot of power. And that means that batteries need to be recharged and replaced regularly. Furthermore, traditional electronics are not always compatible with the environment that they need to be deployed in, whether that is on a plant, in the ground, or on the human body.

A group of researchers at Southeast University and Nanjing University recently got together in an attempt to address these emerging problems. This multidisciplinary team has proposed a novel battery-free wireless sensing system for building passive and maintenance-free IoT networks.

The system draws inspiration from the body structure of animals, utilizing thermal-stimulus responsive materials with tunable stiffness as the "skeleton" to support fragile microwave devices and electronic systems. Additionally, the researchers synthesized a skin-like soft polymer with self-healing properties, excellent strength, and chemical stability, providing a durable encapsulation for the system.

This biomimetic design strategy enables the proposed system to combine flexibility, electromagnetic stability, structural robustness, and self-healing performance. The system also incorporates an ultra-low-power backscatter communication scheme, allowing it to modulate and reflect ambient electromagnetic waves for wireless communication. This approach significantly reduces power consumption, making it possible for the device to operate without batteries.

To address the issue of power supply, the researchers devised an efficient solar-microwave hybrid energy harvester and intelligent power management scheme. This allows the system to capture environmental electromagnetic energy, enabling long-range wireless communication and sensing without relying on traditional power sources.

The proposed system has the potential to simplify the way IoT devices are maintained and deployed in the future. With its battery-free design, maintenance will be greatly reduced. And the bio-inspired design elements will allow these devices to be deployed in a wide range of environments. As technological advancements enable us to scale up IoT networks to ever larger sizes, this system could help to make it more practical to manage those networks.