Periodic Reporting for period 4 - SCATTERERID (Analysis and synthesis of wideband scattered signals from finite-size targets – aspect-independent RF analog footprint)
Reporting period: 2023-03-01 to 2024-08-31
ScattererID has been very prolific in terms of scientific results. It has generated 33 Journal Papers, 41 Conference Papers (including 29 international ones), 8 Invited Papers and 2 Books. It has led to the introduction of the first reconfigurable chipless tag CT; it has demonstrated and used the very high sensitivity of radar measurements to trace temperature by measuring the elongation of resonant scatterers; and it has detected the presence of doping on silicon nanowires... The results on the sensor part are significant, as we have seen how a simple rectangular metal loop can be used for very different applications. The application side of measuring the complex permittivity of materials has led to the setting up of an ERC POC project, the aim of which is to clearly define the possibilities of this approach for a practical use that is very different from what is currently done in industry. The conclusion of each objectif (from the DOA) are now detailed:
About “RF Switches”, the objective was to develop RF switches based on CBRAM technology compatible with printing techniques, where the key success indicators were, for instance, the performance in frequency of the switches or the simplicity of the realization method. We were able to show that it is possible to produce switches based on the CBRAM using a simple commercial printer (thermal transfer) and Nafion.
Regarding the action done on Reconfigurable Chipless tags, the objective was to be able to reconfigure the ID during the tag's use by incorporating switches into chipless tags. Some of the key success indicators were the realization of the first rewritable Chipless tag, the realization of a low-cost rewritable tag, or the realization of a rewritable tag with programming cycles exceeding 100. The main objectives have been achieved.
Regarding “Robust Tags” concept, the objectives were to design, build, and character robust tags compatible with high reading rates whatever the environment. The key success indicators were the introducation of a robust chipless system with a read range more than 30 cm in real environment, or a number of bits higher than 60. Significant progress has been made on the issue of robustness reading. A new family of resonant scatterers designed to have cross-polarisation responses whatever their orientation has been introduced. We also have introduced the concept of a co-polarisation reader with electronic alignment of the equivalent signal emitted by the antenna. A reading distance of more than a meter was obtained. The number of bits was successfully addressed using an imaging approach where a realistic coding capacity of more than 65 bits was achieved.
Regarding “Chipless sensing-tags” the objective was the integration of the sensor functionality into the tag. For example, for one kind of sensor function, nanowires with different dopants were studied. Some of the key success indicators were the realization of the humidity chipless sensing tags, with some specification on the accuracy (+- 5% expected for humidity). This is undoubtedly the action that generated the greatest advances, namely the demonstration of the very good measurement sensitivity that the approach makes it possible to achieve. The principle has been used for a very large number of sensors: temperature, humidity, angle of rotation, water detection, etc., but also for metrology applications such as measuring CTE or the complex permittivity of dielectrics.
Regarding the concept of ”Advanced Chipless tags”, the objective was to realize advanced tags based on the functionalities developed in previous actions. The key success indicators were the realization of the first reconfigurable tag where the switch commutation can be controlled remotely . The study on the remote control of a CBRAM cell was carried out in collaboration with the University of Tokyo. The concept of Motion-Modulated Chipless RFID has been introduced.
Regarding “Gesture Recognition”, the goal was to develop techniques compatible with gesture recognition based on a simple chipless label used as a remote control. Key success indicators were the realization of the first system based on chipless label able to make gesture recognition and the number of different scenarios implementable in practice. The defined objectives were successfully met. Printed tags were used to dismantle the keyboard mode function. For the joystick mode, a specific tag, using triangulation, was introduced to detect its position with the antenna in real-time.
About “RF Switches”, the objective was to develop RF switches based on CBRAM technology compatible with printing techniques, where the key success indicators were, for instance, the performance in frequency of the switches or the simplicity of the realization method. We were able to show that it is possible to produce switches based on the CBRAM using a simple commercial printer (thermal transfer) and Nafion.
Regarding the action done on Reconfigurable Chipless tags, the objective was to be able to reconfigure the ID during the tag's use by incorporating switches into chipless tags. Some of the key success indicators were the realization of the first rewritable Chipless tag, the realization of a low-cost rewritable tag, or the realization of a rewritable tag with programming cycles exceeding 100. The main objectives have been achieved.
Regarding “Robust Tags” concept, the objectives were to design, build, and character robust tags compatible with high reading rates whatever the environment. The key success indicators were the introducation of a robust chipless system with a read range more than 30 cm in real environment, or a number of bits higher than 60. Significant progress has been made on the issue of robustness reading. A new family of resonant scatterers designed to have cross-polarisation responses whatever their orientation has been introduced. We also have introduced the concept of a co-polarisation reader with electronic alignment of the equivalent signal emitted by the antenna. A reading distance of more than a meter was obtained. The number of bits was successfully addressed using an imaging approach where a realistic coding capacity of more than 65 bits was achieved.
Regarding “Chipless sensing-tags” the objective was the integration of the sensor functionality into the tag. For example, for one kind of sensor function, nanowires with different dopants were studied. Some of the key success indicators were the realization of the humidity chipless sensing tags, with some specification on the accuracy (+- 5% expected for humidity). This is undoubtedly the action that generated the greatest advances, namely the demonstration of the very good measurement sensitivity that the approach makes it possible to achieve. The principle has been used for a very large number of sensors: temperature, humidity, angle of rotation, water detection, etc., but also for metrology applications such as measuring CTE or the complex permittivity of dielectrics.
Regarding the concept of ”Advanced Chipless tags”, the objective was to realize advanced tags based on the functionalities developed in previous actions. The key success indicators were the realization of the first reconfigurable tag where the switch commutation can be controlled remotely . The study on the remote control of a CBRAM cell was carried out in collaboration with the University of Tokyo. The concept of Motion-Modulated Chipless RFID has been introduced.
Regarding “Gesture Recognition”, the goal was to develop techniques compatible with gesture recognition based on a simple chipless label used as a remote control. Key success indicators were the realization of the first system based on chipless label able to make gesture recognition and the number of different scenarios implementable in practice. The defined objectives were successfully met. Printed tags were used to dismantle the keyboard mode function. For the joystick mode, a specific tag, using triangulation, was introduced to detect its position with the antenna in real-time.
An overview of the main results obtained during this project has been compiled here:
- A novel methodology for achieving a variable resistance for CBRAM cells for microwave applications has been introduced.
- Electronically rewritable chipless RFID tags have been designed, fabricated through thermal transfer printing on flexible PET substrates and characterized.
- A smart and robust chipless RFID label with identification and touch sensing capabilities has been developed.
- We have shown that contactless characterization of thermal expansion coefficient (CTE) of metals can be realized based on free-space RF measurements. This concept has also been used to convert chipless tags to temperature and humidity sensors.
- We have introduced a new RF approach to Wirelessly Detect Surface Modification of Silicon Nanowires. We have seen the possibility of detecting the presence of grafted molecules on the surface of silicon nanowires with a wireless RF radar approach based on the measurement of the backscattered signal of a resonant structure on which the nanowires are deposited.
- We have worked on the idea of “Optimal Angle in Bistatic Measurement for Chipless Tag Detection Improvement”. We have shown that the use of a bistatic reading configuration by optimizing the angle between the two antennas can enhance the reading performance of the chipless tag for short-range applications.
- A significant work has been done on a new topic about “Motion-Modulated Chipless RFID”. Motion-modulated chipless RFID is presented as an effective backscatter communication method for the identification and sensing of moving objects at large distances (up to 10 m).
- A test bench has been built and automated to perform chipless tag characterization. It is now possible to measure the RCS of objects in 3D.
- We have significantly increased the coding capacity of Chipless tags with a concept of RF imaging reading. We have been able to show that it is quite realistic to obtain the 60-bit bar that was given as an objective in the initial project.
The project has made it possible to set up the ERC POC project RFMatCarac, which aims to demonstrate the application potential of a solution developed in ScattererID around the topic of dielectric characterization in RF. In addition, Idyllic Technology, an LCIS spinoff, with the objective to transfer the laboratory's research about chipless RFID won the CES® 2024 Innovation Awards honoree. This is a marker that a significant part of the results obtained in the ScattererID project can be used in industry.
- A novel methodology for achieving a variable resistance for CBRAM cells for microwave applications has been introduced.
- Electronically rewritable chipless RFID tags have been designed, fabricated through thermal transfer printing on flexible PET substrates and characterized.
- A smart and robust chipless RFID label with identification and touch sensing capabilities has been developed.
- We have shown that contactless characterization of thermal expansion coefficient (CTE) of metals can be realized based on free-space RF measurements. This concept has also been used to convert chipless tags to temperature and humidity sensors.
- We have introduced a new RF approach to Wirelessly Detect Surface Modification of Silicon Nanowires. We have seen the possibility of detecting the presence of grafted molecules on the surface of silicon nanowires with a wireless RF radar approach based on the measurement of the backscattered signal of a resonant structure on which the nanowires are deposited.
- We have worked on the idea of “Optimal Angle in Bistatic Measurement for Chipless Tag Detection Improvement”. We have shown that the use of a bistatic reading configuration by optimizing the angle between the two antennas can enhance the reading performance of the chipless tag for short-range applications.
- A significant work has been done on a new topic about “Motion-Modulated Chipless RFID”. Motion-modulated chipless RFID is presented as an effective backscatter communication method for the identification and sensing of moving objects at large distances (up to 10 m).
- A test bench has been built and automated to perform chipless tag characterization. It is now possible to measure the RCS of objects in 3D.
- We have significantly increased the coding capacity of Chipless tags with a concept of RF imaging reading. We have been able to show that it is quite realistic to obtain the 60-bit bar that was given as an objective in the initial project.
The project has made it possible to set up the ERC POC project RFMatCarac, which aims to demonstrate the application potential of a solution developed in ScattererID around the topic of dielectric characterization in RF. In addition, Idyllic Technology, an LCIS spinoff, with the objective to transfer the laboratory's research about chipless RFID won the CES® 2024 Innovation Awards honoree. This is a marker that a significant part of the results obtained in the ScattererID project can be used in industry.