Periodic Reporting for period 4 - NEW_FUN (New era of printed paper electronics based on advanced functional cellulose)
Reporting period: 2020-03-01 to 2021-05-31
To fulfil the aims of the “Green Deal” of transforming the European Union (EU) into a fair, sustainable, and prosperous society, with a modern, resource-efficient and competitive economy, the development of new emerging technologies, such as those supporting our “digitalized” society, cannot just focus on the performance/cost ratio. It will necessarily consider the technology's environmental impact and sustainability, which includes materials, processes and product end of life. Given this scenario, it seems evident that the same will happen in the electronics industry serving Information and Communication Technology (ICT). High-performance levels will continue to be satisfied by silicon ICs and other crystalline semiconductors. At the same time, some new devices and systems in the future, without the need for such high performance, will be covered by hybrid technologies and low-cost processes. This will be of particular interest for devices that are used for short periods and with low added value, such as biosensors, smart packaging, wearables, all of them serving the demands of the Internet of Things (IoT) concept.
Within this context, the global objective of NewFun was the creation of environmentally friendly advanced functional materials and processes able to result in a new class of paper-based electronic products. The scientific outputs of NewFun have demonstrated new approaches and methodologies to implement electronic circuits, sensors, energy harvesting devices on paper substrates, using cellulose-based materials and nanocomposites. It was demonstrated that cellulose derivatives could be combined with other organic and inorganic materials to create multifunctional nanocomposites compatible with printing techniques. They were formulated in the form of printable inks that did not require post-processing thermal treatments, fully compatible with paper substrates. Cellulose-based electrolyte membranes based on cellulose derivatives, nanofibers and nanocrystals (CNCs) were ionically doped to improve their electrochemical and dielectric response. They were then integrated in new devices like transistors on paper with innovative architectures and photonic transistors shown for the first time in the NewFun. The project demonstrated a holistic approach to the topic of printable, flexible and paper electronics, covering different devices that can be considered building blocks for the integration into more complex systems, all of them made of sustainable materials and fully recyclable/reusable.
Within this context, the global objective of NewFun was the creation of environmentally friendly advanced functional materials and processes able to result in a new class of paper-based electronic products. The scientific outputs of NewFun have demonstrated new approaches and methodologies to implement electronic circuits, sensors, energy harvesting devices on paper substrates, using cellulose-based materials and nanocomposites. It was demonstrated that cellulose derivatives could be combined with other organic and inorganic materials to create multifunctional nanocomposites compatible with printing techniques. They were formulated in the form of printable inks that did not require post-processing thermal treatments, fully compatible with paper substrates. Cellulose-based electrolyte membranes based on cellulose derivatives, nanofibers and nanocrystals (CNCs) were ionically doped to improve their electrochemical and dielectric response. They were then integrated in new devices like transistors on paper with innovative architectures and photonic transistors shown for the first time in the NewFun. The project demonstrated a holistic approach to the topic of printable, flexible and paper electronics, covering different devices that can be considered building blocks for the integration into more complex systems, all of them made of sustainable materials and fully recyclable/reusable.
The main goal of the NewFun project was to combine cellulose with nanomaterials to create new functional materials to be implemented both as physical support and active components in electronic, electrochemical, photonic and energy harvesting devices (see picture 1). The main achievements of this project are listed below.
Cellulose nanocomposites: Carbon fibers (CFs) and multiwall carbon nanotubes (MWCNTs) were combined with a cellulose derivative (carboxymethyl cellulose – CMC) towards the development of screen-printed temperature sensors. When CMC was combined with ZnO nanoparticles it was possible to develop a radically new approach for semiconductor printed layers on paper not requiring any post-printing annealing process.
Development of cost-effective and up scalable-printing technologies: NewFun has proposed for the first time the pen-on-paper approach to deposit semiconductor layers on paper at low temperature. This way it is possible to, literally, “write” electronic components on paper, such as UV sensors and transistors.
Development of cellulose-based hydrogel electrolytes (CHEs): These CHEs present a unique combination of electrochemical and dielectric characteristics, being also self-healable and fully recyclable. They were successfully implemented as high-capacitance gate dielectrics in oxide-based transistors.
Paper layers/substrates from functional cellulose nanocomposites/nanocrystals (CNCs): The precursor for the formation of the cellulose-based hydrogel electrolytes has been used to impregnate paper matrices made of purified cellulose fibers. The goal is to create a paper-like structure with high ionic conductivity capable of being used as high capacitance dielectrics in transistors. When using CNCs, these dielectrics also have photonic functionalities.
Production of optimized transistors, circuits and sensors on paper: New architectures for transistors and circuits with unique functionalities (dual gate, color changing and photonic transistors/circuits) and sensors were developed and implemented.
The most significant achievements and recognition of the work performed within NewFun were disseminated and exploited through publications, outreach, events and media. Some hughlights are listed below.
Publications: NewFun delivered publications in journals of high impact factor journals, among the most recognized in the field of materials science, resulting in some covers (see picture 2).
Outreach: The NewFun scientific outputs were used to prepare a practical exercise in the International Physics Olympiads 2018 (IPhO2018). More than 400 students from around the world gathered in a pavilion to complete and assemble a paper circuit and obtained their electrical characteristics (see picture 2)
Events: The PI was the main organizer of symposium Q at the European Materials Research Society Spring Meeting 2021 (https://www.european-mrs.com/cellulose-electronics-and-photonics-new-challenge-materials-new-opportunity-devices-iii-emrs).
Media: Part of the NewFun team has entered an acceleration programme in 2018 (HiTechSeed 2018 edition, https://hiseedtech.com and https://www.youtube.com/watch?v=Ykv1SZPS_II&t=44s) with a project called GlassLink that has attracted the attention of the media (https://visao.sapo.pt/exameinformatica/videos-ei/reporterei/2018-11-19-glasslink-a-pelicula-portuguesa-que-bloqueia-a-luz-e-o-calor/).
Cellulose nanocomposites: Carbon fibers (CFs) and multiwall carbon nanotubes (MWCNTs) were combined with a cellulose derivative (carboxymethyl cellulose – CMC) towards the development of screen-printed temperature sensors. When CMC was combined with ZnO nanoparticles it was possible to develop a radically new approach for semiconductor printed layers on paper not requiring any post-printing annealing process.
Development of cost-effective and up scalable-printing technologies: NewFun has proposed for the first time the pen-on-paper approach to deposit semiconductor layers on paper at low temperature. This way it is possible to, literally, “write” electronic components on paper, such as UV sensors and transistors.
Development of cellulose-based hydrogel electrolytes (CHEs): These CHEs present a unique combination of electrochemical and dielectric characteristics, being also self-healable and fully recyclable. They were successfully implemented as high-capacitance gate dielectrics in oxide-based transistors.
Paper layers/substrates from functional cellulose nanocomposites/nanocrystals (CNCs): The precursor for the formation of the cellulose-based hydrogel electrolytes has been used to impregnate paper matrices made of purified cellulose fibers. The goal is to create a paper-like structure with high ionic conductivity capable of being used as high capacitance dielectrics in transistors. When using CNCs, these dielectrics also have photonic functionalities.
Production of optimized transistors, circuits and sensors on paper: New architectures for transistors and circuits with unique functionalities (dual gate, color changing and photonic transistors/circuits) and sensors were developed and implemented.
The most significant achievements and recognition of the work performed within NewFun were disseminated and exploited through publications, outreach, events and media. Some hughlights are listed below.
Publications: NewFun delivered publications in journals of high impact factor journals, among the most recognized in the field of materials science, resulting in some covers (see picture 2).
Outreach: The NewFun scientific outputs were used to prepare a practical exercise in the International Physics Olympiads 2018 (IPhO2018). More than 400 students from around the world gathered in a pavilion to complete and assemble a paper circuit and obtained their electrical characteristics (see picture 2)
Events: The PI was the main organizer of symposium Q at the European Materials Research Society Spring Meeting 2021 (https://www.european-mrs.com/cellulose-electronics-and-photonics-new-challenge-materials-new-opportunity-devices-iii-emrs).
Media: Part of the NewFun team has entered an acceleration programme in 2018 (HiTechSeed 2018 edition, https://hiseedtech.com and https://www.youtube.com/watch?v=Ykv1SZPS_II&t=44s) with a project called GlassLink that has attracted the attention of the media (https://visao.sapo.pt/exameinformatica/videos-ei/reporterei/2018-11-19-glasslink-a-pelicula-portuguesa-que-bloqueia-a-luz-e-o-calor/).
The scientific outputs and publications of NewFun describe real breakthroughs in the field of cellulose-based electronics and photonics. Among the set of results and achievement already described, the ones that are considered the major breakthroughs regarding the state of the art are:
- A new approach in developing cellulose electrolytic membranes to be used (and reused) in electrolyte gated transistors. These electrolytic hydrogel membranes can be attached and easily peeled off from the substrates, are self-healable, and can be regenerated without significant loss of performance. If also considering the electrochemical performance of the membranes it results in a unique combination of characteristics not reported before NewFun.
- The printing and pen-on-paper deposition (“writing”) of inorganic semiconductor layers not requiring annealing was something reported for the first time by the NewFun team. They were successfully implemented in UV sensors, transistors and circuits printed on paper.
- The self-assembly capability of cellulose nanocrystals was explored to create new light polarization sensitive transistors and photodetectors that integrate natural materials and nature-inspired structures that are selective to light polarization. The integration in transistors allowed for the development of devices that are modulated simultaneously by electric and light signals (polarization sensitive), demonstrated for the first time by the NewFun team.
- A new approach in developing cellulose electrolytic membranes to be used (and reused) in electrolyte gated transistors. These electrolytic hydrogel membranes can be attached and easily peeled off from the substrates, are self-healable, and can be regenerated without significant loss of performance. If also considering the electrochemical performance of the membranes it results in a unique combination of characteristics not reported before NewFun.
- The printing and pen-on-paper deposition (“writing”) of inorganic semiconductor layers not requiring annealing was something reported for the first time by the NewFun team. They were successfully implemented in UV sensors, transistors and circuits printed on paper.
- The self-assembly capability of cellulose nanocrystals was explored to create new light polarization sensitive transistors and photodetectors that integrate natural materials and nature-inspired structures that are selective to light polarization. The integration in transistors allowed for the development of devices that are modulated simultaneously by electric and light signals (polarization sensitive), demonstrated for the first time by the NewFun team.