Periodic Reporting for period 1 - PIC2D (Printable Inks Made of Conductive 2D Materials Beyond Graphene for Micro-Electrochemical Devices)
Reporting period: 2020-09-01 to 2022-08-31
Wearable technology, the most important part of Internet of Things (IoTs), is facing a rapid development. The main component of the wearable electronics is the sensor, able to provide useful insights into the performance and health of individuals. Early efforts of wearable sensors is mainly used for sensing physical signals that monitored mobility and vital signs, such as steps, calories burned or heart rate. Electrochemical sensor (ECS), an integrated device that provides analytical information, either quantitative or semi-quantitative, using a biorecognition strategy involving an electrochemical transducer, provides a powerful analytical technique able to measure broad range of important biochemical compounds such as glucose, uric acid, and amino acids.
This project aims at bringing the much-needed step change in flexible and wearable electronics by developing a new industrially driven inkjet printing technology for the definition of electronic devices for sensing. The key challenge is therefore to develop printable ink formulations with highly tuneable property, functionality and printability suitable for sensing. This project aims at developing printable ink formulations, exploiting 2D materials beyond graphene with properties suitable for the fabrication of a wide range of printed sensors. This research ranges from material development to target applications, hence the results are expected to raise strong interest from both the research community and industry.
This project aims at bringing the much-needed step change in flexible and wearable electronics by developing a new industrially driven inkjet printing technology for the definition of electronic devices for sensing. The key challenge is therefore to develop printable ink formulations with highly tuneable property, functionality and printability suitable for sensing. This project aims at developing printable ink formulations, exploiting 2D materials beyond graphene with properties suitable for the fabrication of a wide range of printed sensors. This research ranges from material development to target applications, hence the results are expected to raise strong interest from both the research community and industry.
Exfoliation in water of heaxgonal Boron Nitride (h-BN), Mxene and InSe was successfully achieved. The dispersions are stable for several weeks and have concentrations above 0.1 mg/mL. The ink was characterized with several techniques, such as XPS, FTIR, SEM, and EDS. The lateral size and thickness distributions of the flakes was measured by AFM, showing that most nanosheets have thickness below 15 nm, indicating efficient exfoliation.
The dispersions were made inkjet printable by performing solvent exchange with a printable water-based solvent developed in our group. The ink was deposited on silicon and on paper at different printing passes and the thickness vs number of printing passes relationship was extracted. The printed features are unform and sharp, indicating excellent printability.
The h-BN ink was used to demonstrate a wearable and wireless impedance-based humidity sensor, which shows enhanced sensitivity towards relative humidity, fast response, no appreciable hysteresis and cross-sensitivity in the range of 25–60°C. We finally demonstrate that the h-BN based sensor is able to monitor the whole breathing cycle process of exhaling and inhaling, hence enabling to record in real time the subtlest changes of respiratory signals associated with different daily activities as well as various symptoms of flu, without requiring any direct contact with the individual. A wireless demonstrator was made by integrating the device onto a face mask. The same approach was then extended to 2D Titanium Oxide inks, previously developed in our group.
The Mxene and inSe inks were used to demonstrate fully printed photodetectors with relatively good performance - further optimization is needed.
Due to the lockdown and maternity leave, the dissemination was somehow limited. The work was presented as poster and oral in few conferences and a press release was made after publication and shared on Linkedin.
The dispersions were made inkjet printable by performing solvent exchange with a printable water-based solvent developed in our group. The ink was deposited on silicon and on paper at different printing passes and the thickness vs number of printing passes relationship was extracted. The printed features are unform and sharp, indicating excellent printability.
The h-BN ink was used to demonstrate a wearable and wireless impedance-based humidity sensor, which shows enhanced sensitivity towards relative humidity, fast response, no appreciable hysteresis and cross-sensitivity in the range of 25–60°C. We finally demonstrate that the h-BN based sensor is able to monitor the whole breathing cycle process of exhaling and inhaling, hence enabling to record in real time the subtlest changes of respiratory signals associated with different daily activities as well as various symptoms of flu, without requiring any direct contact with the individual. A wireless demonstrator was made by integrating the device onto a face mask. The same approach was then extended to 2D Titanium Oxide inks, previously developed in our group.
The Mxene and inSe inks were used to demonstrate fully printed photodetectors with relatively good performance - further optimization is needed.
Due to the lockdown and maternity leave, the dissemination was somehow limited. The work was presented as poster and oral in few conferences and a press release was made after publication and shared on Linkedin.
Solution processed h-BN has been hardly investigated for humidity sensing because it is hydrophobic, so it cannot be easily exfoliated in water and has low sensitivity towards water molecules. In this work we used supramolecular chemistry in order to achieve efficient exfoliation of the material in water and to enhance its sensitivity, hence going beyond state of art. We integrated the device onto a face mask, by demonstrating wireless monitoring of the full breathing process.
This device can have strong impact for the society. Indeed, even the simple moisture sensing of exhaled breath can provide important physiological information on an individual, related to cardiac, neurological and pulmonary conditions, as well as certain types of illness. Furthermore, the technology can be tailored to achieve selectivity towards biomarkers found in the breath, associated to diseases.
Overall our results can help enabling transformative changes in healthcare associated to the ability to continuously monitor the human health status, by realising personalized diagnostics and therapeutic treatments.
This device can have strong impact for the society. Indeed, even the simple moisture sensing of exhaled breath can provide important physiological information on an individual, related to cardiac, neurological and pulmonary conditions, as well as certain types of illness. Furthermore, the technology can be tailored to achieve selectivity towards biomarkers found in the breath, associated to diseases.
Overall our results can help enabling transformative changes in healthcare associated to the ability to continuously monitor the human health status, by realising personalized diagnostics and therapeutic treatments.