Development of a flexible battery-free geolocation tag based on advanced materials

In a world of IoT’s, traceability and digitalization, the use of electronic devices is becoming mainstream and generates valuable data for millions of companies and consumers, but at the expense of the environment, all using batteries and non-renewable resources.

Indeed, the main hurdles facing electronics devices are power consumption and miniaturisation. Emerging systems are therefore working on electronic components with ultra-low power consumption or using energy harvesting techniques to have a long lifespan. Energy Harvesting is the new approach to avoid batteries, their replacement and thus allow size reduction. In addition, face to the development of alternative systems and electronic devices, the next in line for the release are the flexible and smart geolocation tags on paper-based substrates. Thanks to its high recyclability, the paper arises as an ecological alternative.

Uwinloc has investigated an accurate solution to geolocate assets through Ultra Wide Band technology without any battery usage. The operation without any battery is possible thanks to far-field wireless power transmission. Apart from the actual commercialised tag, the main goal for Uwinloc is to develop a flexible and low-cost tag to target new markets, to address new use cases, volumes and shape of asset.

This solution will require a less complicated and less expensive manufacturing process. Our expertise in the field of energy harvesting, has enabled us to develop a new miniaturised chip with better sensitivity. This great improvement can now offer a range more than 30 meters. However, the main constraint in any wireless device is the optimisation of the antenna to efficiently receive or transmit the signal. Uwinloc’s solution is based on two antennas:

• Ultra-High Frequency (UHF) used for harvesting the surrounding electromagnetic wave
• Ultra-Wide Band (UWB) frequency at 4 GHz for transmitting the position to a dedicated beacon in the same area.

Through the MADRAS project, Uwinloc is participating as a demonstrator for a new flexible geotracking tag. The important innovation of the demo is achieved by means of a specific production process. It goes from the choice of the material based on nanocellulose foil, the printing process and the hybridisation techniques. Based on advanced material and injection moulding effect on antenna’s performances, an improvement on the design and accurate characterisation of the antenna is suitable for a good sensitivity of the tags.

In order to harvest enough surrounding energy for the location tag, an omnidirectional UHF antenna with high radiation efficiency is required. The antenna designer also faces to many constraints when targeting to have a low-profile antenna in a thin flexible substrate. The dielectric parameter of the substrate (permittivity and losses) depending on the frequency, greatly affect the impedance and the radiation efficiency of the antenna.

Then, the in-moulded methodology developed at Eurecat is applied over the antennas and control unit assembly. The material should be appropriately chosen to both have interesting radiofrequency transparency and be flexible. Thermoplastic polyuethante (TPU) material is a good candidate and has the lowest processing temperature.

Once the antenna has been designed, they are measured in anechoic chamber to avoid any reflection of electromagnetic waves and reproduce free space conditions as in the simulations. Measurements of the antennas in terms of coupling, radiation efficiency and gain are performed to the LAAS-CNRS as part of the scientific partnership.

Through the MADRAS project, Uwinloc is participating as a demonstrator for a new flexible geotracking tag. The important innovation of the demo is achieved by means of a specific production process. It goes from the choice of the material based on nanocellulose foil, the printing process and the hybridisation techniques. Based on advanced material and injection moulding effect on antenna’s performances, an improvement on the design and accurate characterisation of the antenna is suitable for a good sensitivity of the tags.

In order to harvest enough surrounding energy for the location tag, an omnidirectional UHF antenna with high radiation efficiency is required. The antenna designer also faces to many constraints when targeting to have a low-profile antenna in a thin flexible substrate. The dielectric parameter of the substrate (permittivity and losses) depending on the frequency, greatly affect the impedance and the radiation efficiency of the antenna.

Then, the in-moulded methodology developed at Eurecat is applied over the antennas and control unit assembly. The material should be appropriately chosen to both have interesting radiofrequency transparency and be flexible. Thermoplastic polyuethante (TPU) material is a good candidate and has the lowest processing temperature.

Once the antenna has been designed, they are measured in anechoic chamber to avoid any reflection of electromagnetic waves and reproduce free space conditions as in the simulations. Measurements of the antennas in terms of coupling, radiation efficiency and gain are performed to the LAAS-CNRS as part of the scientific partnership.

This new generation of low-cost and flexible tags allows targeting new markets and special applications in retail, logistics, or healthcare, with a whole new range of assets such as cardboard boxes, tools, barrels, pipelines…

UWINLOC is currently addressing the industry but cannot meet 100% of its customer’s needs due to the current form factor of its tags. One of the remaining needs of the industry is to track a large volume of tools to help operators spend less time looking for them when they are lost. At the main time, to have the right tools in the right place to avoid non-conformities. This new flexible tag will enable the traceability and location of these tools at any time and will help to achieve real time inventory and better stock management while avoiding overstocks.

Another great example of application is in logistics. A flexible and low-cost tag that can be used as a consumable to continuously track, locate, and manage the work in progress of millions of cardboard boxes or containers, improving process quality and reducing lead times.

Another great example of application is in logistics. A flexible and low-cost tag that can be used as a consumable to continuously track, locate, and manage the work in progress of millions of cardboard boxes or containers, improving process quality and reducing lead times.