Wireless fast charging for the future of IoT solutions

As part of his degree project in Electronic Systems, Engineering Physics student Franz Wikner has been exploring inductive fast charging for encapsulated Internet of Things devices. The aim is to extend the lifetime of devices and create robust systems that can protect against moisture and dust.

Internet of Things devices are often battery-powered and well encapsulated to withstand harsh industrial conditions. It is a challenge to get them to perform their tasks for long periods without being disrupted by downtime due to battery changes. Ideally, the devices should be charged wirelessly and quickly. This extends the lifespan of the systems and reduces the number of systems that need to be discarded.

“If we can avoid disruption at every battery change, we can extend the life of the devices. And if the systems are properly encapsulated, they can be protected from moisture or dust. 'The method I used ensures completely sealed enclosures and minimizes the risk of system damage or calibration problems when changing batteries,” says Franz Wikner, who studied engineering physics.

“Similar technologies are already used in everyday electronics, such as phone chargers, but my work takes the step towards higher power and greater reliability for IoT devices.”

Greening battery use

In his project, Franz Wikner has simulated and tested electromagnetic fields, power transfer and efficiency of transmitter and receiver systems consisting of different types of coils. One coil is a traditional transformer-like coil and the other a planar spiral coil, enabling the transmission of electromagnetic energy through the induced electric field. To maximize efficiency, the coils have been compensated with series-connected capacitors, achieving high power transfer with up to 92% efficiency.

“The technology I have developed has parallels in the use of inductive electric car chargers, where larger coils and higher powers are used over longer distances. By applying these principles to IoT devices, they could be charged with at least 30 watts. This in turn improves or extends the use of IoT in different industries. The lifetime of the systems is extended and fewer systems are discarded,” explains Franz Wikner.

How has it been to do your thesis in a live project in academia?

“It has been both challenging and rewarding. Collaborating with professors and PhD students has not only given me deeper knowledge, but also an insight into the dynamics of the research process. Being part of academic discussions has challenged my problem-solving skills and given me a new understanding of how research drives innovation and knowledge.”