Periodic Reporting for period 1 - GRETA (GREEN, ORGANIC AND PRINTED ULTRA-HIGH FREQUENCY IDENTIFICATION TAGS)
Berichtszeitraum: 2025-01-01 bis 2025-12-31
GRETA will lay the foundation of the first green, printed and flexible organic wireless identification tag operating at Ultra-High Frequency (UHF, 300 MHz – 3 GHz). The long-term vision is to enable remote powering and readout of tags up to meters distance range, as required in logistics and security, without the need of a battery and with drastically reduced lifecycle impact and costing with respect to any available passive radio-frequency identification (RFID) technology. To achieve such overarching goal, GRETA aims at groundbreaking progress along two specific complementary actions.
- Action 1: Removing present barriers preventing sustainability of printed organic electronics, by tackling the most environmental and economically impactful aspects, yet seldom addressed, of organics synthesis and processing.
- Action 2: Demonstrating unprecedented UHF operation of printed organic electronics.
Within such actions, GRETA planned the following measurable Objectives.
Objective 1. Green synthesis and development of sustainable and biodegradable materials (Action 1).
Objective 2. Sustainable inks formulations for large-area printing tools (Action 1).
Objective 3. UHF electronics based on sustainable printed organic semiconductors (Action 2).
Objective 4. Enable an eco-designed, printed UHF wireless tag with sustainable lifecycle.
Objective 4 is dedicated to demonstrators of the entire effort: GRETA UHF tag, demonstrating rectification of a 400 MHz wave to enable a code generator, and GRETA UHF logic, demonstrating a sustainable printed integrated 4-bit shift register.
GRETA fulfills the scope of the EIC Pathfinder Challenge “Responsible Electronics” as it serves emerging digitalization needs in logistics, healthcare and security without adding e-waste, independent from the silicon industry and from any critical raw material, and delivering safe materials for the environment.
- Action 1: Removing present barriers preventing sustainability of printed organic electronics, by tackling the most environmental and economically impactful aspects, yet seldom addressed, of organics synthesis and processing.
- Action 2: Demonstrating unprecedented UHF operation of printed organic electronics.
Within such actions, GRETA planned the following measurable Objectives.
Objective 1. Green synthesis and development of sustainable and biodegradable materials (Action 1).
Objective 2. Sustainable inks formulations for large-area printing tools (Action 1).
Objective 3. UHF electronics based on sustainable printed organic semiconductors (Action 2).
Objective 4. Enable an eco-designed, printed UHF wireless tag with sustainable lifecycle.
Objective 4 is dedicated to demonstrators of the entire effort: GRETA UHF tag, demonstrating rectification of a 400 MHz wave to enable a code generator, and GRETA UHF logic, demonstrating a sustainable printed integrated 4-bit shift register.
GRETA fulfills the scope of the EIC Pathfinder Challenge “Responsible Electronics” as it serves emerging digitalization needs in logistics, healthcare and security without adding e-waste, independent from the silicon industry and from any critical raw material, and delivering safe materials for the environment.
GREEN SYNTHESIS OF ORGANIC SEMICONDUCTORS
The synthetic access to known and performing p and n-type polymeric materials was redesigned, dramatically reducing both E-Factor and atom economy. Key features of the approach where: a) removal of toxic/hazardous reagents, b) minimization of VOCs, c) improvement of yields through process intensification; d) use of water as the main solvent.
SUSTAINABLE SUBSTRATES
The inherent roughness of paper and cellulose-based substrates, making them not compatible with thin-film printed electronics, was tackled by developing different planarization layers. Multilayered structures using paper/cellulose matrices compatible with various printing techniques (e.g. screen printing and inkjet printing) were developed. The prepared substrates are flexible, with a surface roughness < 100 nm and thicknesses in the 150 to 200 µm range. Promising candidates for inkjet printing of tag components were identified.
SUSTAINABLE DIELECTRICS
A sustainable and solution-based process to fabricate ultrathin dielectric films was developed starting from cellulose-derived materials. The films can be easily released in water and transferred onto different substrates, enabling the fabrication of flexible and high-capacitance capacitors. The resulting devices showed stable electrical behavior and capacitance values exceeding the project targets.
UHF COMPONENTS
Two specific challenges were tackled: i) engineering of UHF devices based on solution-processed high-mobility organic semiconducting blends and ii) development of inkjet printing formulations and printing protocols of the same blends. The 1st activity led to the development of short-channel OFETs, with micron-sized direct-written metal electrodes, achieving a transition frequency in the VHF range with reduce operation voltage. The 2nd task delivered OFETs based on inkjet printed semiconductor blend with charge mobility of 8 cm2/Vs in long-channel devices, in line with spin-coated samples.
UHF antennas were designed and fabricated using highly conductive graphene sheets on sustainable paper substrates. The performance of the realized antennas operating at 400 MHz and 433 MHz was validated, obtaining S11 values (reflection coefficient) of −8 dB and −12 dB, respectively. A graphene-based antenna operating at 866 MHz was also designed and fabricated on a paper substrate, then validated using a commercially available UHF RFID EM4325 chip and UHF RFID reader, achieving a communication range of up to 6.5 m.
PRINTED LOGIC
The development of complementary printed organic logic circuits was approached by transitioning to an inkjet printing tool more suitable for reliable, high-yield large-area processing. Source and drain gold contacts arrays were printed with high yield from a water based ink, and validated in reference p-type and n-type OFETs.
LCA
Environmental design guidelines based on an eco-design approach were developed, aligned with ESPR, Green Chemistry principles, Safe and Sustainable by Design, and circular electronics frameworks. Relevant indicators were defined, and quantitative metrics such as E-factor and atom economy were included to assess polymer semiconductor synthesis. Environmental benchmarks for materials and devices were developed, selecting reference organic materials and performing LCAs, as well as establishing an RFID tag benchmark with different antenna materials. The eco-design methodology was applied to assess green synthesis protocols and antenna manufacturing, comparing results with benchmarks, identifying hotspots, and sharing findings with project partners to guide more sustainable material and design choices.
ELECTRONIC DESIGN
The design specifications for the organic UHF tag circuit were defined, addressing both the overall system and the individual sub‑components, including the antenna, organic rectifier, code generator, and backscatter modulator. A suitable architecture for the target demonstrator has also been proposed, integrating all these sub‑components using an heterogeneous approach. As the development of the complementary OFETs technology may lead to unforeseen performance limitations, several alternative UHF tag architectures have been proposed as suitable mitigation strategies.
The synthetic access to known and performing p and n-type polymeric materials was redesigned, dramatically reducing both E-Factor and atom economy. Key features of the approach where: a) removal of toxic/hazardous reagents, b) minimization of VOCs, c) improvement of yields through process intensification; d) use of water as the main solvent.
SUSTAINABLE SUBSTRATES
The inherent roughness of paper and cellulose-based substrates, making them not compatible with thin-film printed electronics, was tackled by developing different planarization layers. Multilayered structures using paper/cellulose matrices compatible with various printing techniques (e.g. screen printing and inkjet printing) were developed. The prepared substrates are flexible, with a surface roughness < 100 nm and thicknesses in the 150 to 200 µm range. Promising candidates for inkjet printing of tag components were identified.
SUSTAINABLE DIELECTRICS
A sustainable and solution-based process to fabricate ultrathin dielectric films was developed starting from cellulose-derived materials. The films can be easily released in water and transferred onto different substrates, enabling the fabrication of flexible and high-capacitance capacitors. The resulting devices showed stable electrical behavior and capacitance values exceeding the project targets.
UHF COMPONENTS
Two specific challenges were tackled: i) engineering of UHF devices based on solution-processed high-mobility organic semiconducting blends and ii) development of inkjet printing formulations and printing protocols of the same blends. The 1st activity led to the development of short-channel OFETs, with micron-sized direct-written metal electrodes, achieving a transition frequency in the VHF range with reduce operation voltage. The 2nd task delivered OFETs based on inkjet printed semiconductor blend with charge mobility of 8 cm2/Vs in long-channel devices, in line with spin-coated samples.
UHF antennas were designed and fabricated using highly conductive graphene sheets on sustainable paper substrates. The performance of the realized antennas operating at 400 MHz and 433 MHz was validated, obtaining S11 values (reflection coefficient) of −8 dB and −12 dB, respectively. A graphene-based antenna operating at 866 MHz was also designed and fabricated on a paper substrate, then validated using a commercially available UHF RFID EM4325 chip and UHF RFID reader, achieving a communication range of up to 6.5 m.
PRINTED LOGIC
The development of complementary printed organic logic circuits was approached by transitioning to an inkjet printing tool more suitable for reliable, high-yield large-area processing. Source and drain gold contacts arrays were printed with high yield from a water based ink, and validated in reference p-type and n-type OFETs.
LCA
Environmental design guidelines based on an eco-design approach were developed, aligned with ESPR, Green Chemistry principles, Safe and Sustainable by Design, and circular electronics frameworks. Relevant indicators were defined, and quantitative metrics such as E-factor and atom economy were included to assess polymer semiconductor synthesis. Environmental benchmarks for materials and devices were developed, selecting reference organic materials and performing LCAs, as well as establishing an RFID tag benchmark with different antenna materials. The eco-design methodology was applied to assess green synthesis protocols and antenna manufacturing, comparing results with benchmarks, identifying hotspots, and sharing findings with project partners to guide more sustainable material and design choices.
ELECTRONIC DESIGN
The design specifications for the organic UHF tag circuit were defined, addressing both the overall system and the individual sub‑components, including the antenna, organic rectifier, code generator, and backscatter modulator. A suitable architecture for the target demonstrator has also been proposed, integrating all these sub‑components using an heterogeneous approach. As the development of the complementary OFETs technology may lead to unforeseen performance limitations, several alternative UHF tag architectures have been proposed as suitable mitigation strategies.
1) New and advantageous synthetic access to diketopyrrolopyrrole molecular and polymeric materials. Advantages in synthetic efficiency and access to derivatives not otherwise obtainable. Manuscript in preparation (UNIMIB - M. Crosta, L. Beverina et al 2026)
2) OFETs based on inkjet printed organic semiconductor with the highest mobility reported to date, 8 cm2/Vs, without recurring to substrate pre-patterning processes. Manuscript in preparation (IIT - M. Cambiaggio, M. Caironi et al., 2026).
3) p‐type OFETs based on semiconducting blend realized through a combination of direct‐writing and solution‐processing techniques exhibiting transition frequency (fT) in the VHF, with a record high voltage normalized fT for organic transistors. Key to the result are a reduced contact resistance and submicron gate overlaps, minimizing parasitic gate capacitances. Manuscript in preparation (IIT, TUE - T. Losi, E. Cantatore, M. Caironi et al., 2026).
4) Graphene based UHF RFID passive tag antenna on a paper substrate with enhanced reading range, 6.5 meters in lab conditions. The key to this result is the use of a highly conductive graphene sheet (σ > 2.6 × 10⁶ S/m) on different paper substrates provided by ALMA. Manuscript in preparation (FTN S. Sarang, G. M Stojanovic et al., 2026).
2) OFETs based on inkjet printed organic semiconductor with the highest mobility reported to date, 8 cm2/Vs, without recurring to substrate pre-patterning processes. Manuscript in preparation (IIT - M. Cambiaggio, M. Caironi et al., 2026).
3) p‐type OFETs based on semiconducting blend realized through a combination of direct‐writing and solution‐processing techniques exhibiting transition frequency (fT) in the VHF, with a record high voltage normalized fT for organic transistors. Key to the result are a reduced contact resistance and submicron gate overlaps, minimizing parasitic gate capacitances. Manuscript in preparation (IIT, TUE - T. Losi, E. Cantatore, M. Caironi et al., 2026).
4) Graphene based UHF RFID passive tag antenna on a paper substrate with enhanced reading range, 6.5 meters in lab conditions. The key to this result is the use of a highly conductive graphene sheet (σ > 2.6 × 10⁶ S/m) on different paper substrates provided by ALMA. Manuscript in preparation (FTN S. Sarang, G. M Stojanovic et al., 2026).