Aerosol Jet Printing (AJP) is an additive manufacturing technology capable of depositing functional materials with micrometric resolution on planar, flexible and three-dimensional substrates.
Our research focuses on the use of Aerosol Jet Printing and other direct-write additive manufacturing technologies for the fabrication of sensors and electronic devices, with particular attention to process optimization, functional materials, unconventional substrates, curing techniques and metrological characterization.
The activity combines sensor design, printing technology, electronic measurement and materials characterization to investigate how manufacturing parameters affect the electrical, geometrical and sensing properties of printed devices.
Aerosol Jet Printing of Sensors
Aerosol Jet Printing enables the direct fabrication of conductive and functional structures without conventional masks, photolithography or subtractive manufacturing processes.
The technology is particularly attractive for sensors because functional materials can be deposited directly onto the final component, including surfaces that cannot easily be processed using conventional microfabrication technologies.
Our research activities include:
- Aerosol Jet Printing of sensors
- direct-write fabrication of electronic devices
- printed resistive sensors
- printed strain gauges
- printed temperature sensors
- printed electrodes and microelectrodes
- printing on flexible substrates
- printing on three-dimensional surfaces
- integration of sensors directly onto functional components
Printing on Flexible, 3D and Temperature-Sensitive Substrates
One of the main advantages of additive manufacturing is the possibility of integrating sensors directly onto unconventional substrates and three-dimensional objects.
Our research has investigated the fabrication of printed sensors on polymeric surfaces, cellulose-based materials, flexible substrates and low-melting-point plastics.
Special attention is devoted to the interaction between the printing process and the substrate, including surface morphology, adhesion, thermal limitations and geometrical effects.
This approach enables the development of embedded and conformal sensors for applications including biomedical devices, smart orthoses, aerospace components, smart packaging and industrial systems.
Functional Inks and Nanomaterials
The electrical and sensing performance of printed devices strongly depends on the properties of the deposited materials.
Our research investigates conventional conductive inks as well as emerging functional nanomaterials, including:
- silver nanoparticle inks
- conductive nanomaterials
- MXene-based inks
- functionalized inks for chemical and electrochemical sensing
- nanostructured sensing layers
Particular attention is devoted to the relationship between ink properties, printing parameters, deposited geometry and resulting electrical characteristics.
Curing and Post-Processing
Printed conductive structures generally require a post-processing step to obtain the required electrical and mechanical properties.
Our research investigates both conventional thermal treatments and photonic curing, particularly for substrates that cannot withstand high temperatures.
The effects of curing conditions are studied through measurements of:
- electrical resistance
- resistivity
- Temperature Coefficient of Resistance (TCR)
- geometrical stability
- repeatability
- substrate degradation
- sensor performance
These studies are particularly important when printed conductive structures are used directly as sensing elements.
Geometrical and Metrological Characterization
Printed sensors introduce specific measurement challenges because their performance depends not only on the sensing material but also on the manufacturing process.
For this reason, a significant part of our research is devoted to the metrological characterization of printed structures and additive manufacturing processes.
Investigated parameters include:
- printed line width and thickness
- geometrical accuracy
- electrical resistance and resistivity
- printing repeatability
- manufacturing tolerances
- temperature dependence
- substrate effects
- coating effects
- uncertainty sources
The objective is to establish reliable relationships between printing parameters, geometry, material properties and sensor performance.
Selected Publications
Journal Articles
Printed Strain Gauge on 3D and Low-Melting Point Plastic Surface by Aerosol Jet Printing and Photonic Curing
M. Borghetti, M. Serpelloni, E. Sardini
Sensors, 19, 4220, 2019.
This work demonstrates the direct fabrication of a strain gauge on a three-dimensional, low-melting-point polymer surface using Aerosol Jet Printing combined with photonic curing.
DOI: 10.3390/s19194220 | Download PDF
Printed Smart Devices on Cellulose-Based Materials by Means of Aerosol-Jet Printing and Photonic Curing
M. Serpelloni, E. Cantù, M. Borghetti, E. Sardini
Sensors, 20, 841, 2020.
The study investigates the fabrication of printed electronic devices on different cellulose-based substrates and the use of photonic curing for processing temperature-sensitive materials.
DOI: 10.3390/s20030841 | Download PDF
Temperature Influence on Ti3C2Tx Lines Printed by Aerosol Jet Printing
M. Borghetti, M. Serpelloni, E. Sardini, D. Spurling, V. Nicolosi
Sensors and Actuators A: Physical, 332, 113185, 2021.
This work investigates the temperature-dependent electrical behavior of Aerosol Jet printed Ti3C2Tx MXene structures, contributing to the characterization of emerging functional materials for printed sensors.
DOI: 10.1016/j.sna.2021.113185 | Download PDF
Evaluation of the Curing Process Effects on the TCR of Temperature Sensors Printed by Aerosol Jet Printing
T. Fapanni, H. Elbidweihy, D. Zappa, E. Comini, E. Sardini, M. Serpelloni
IEEE Sensors Journal, 23, pp. 16625–16632, 2023.
The paper analyzes the influence of the curing process on the Temperature Coefficient of Resistance (TCR) of Aerosol Jet printed temperature sensors, highlighting the relationship between manufacturing conditions and sensor performance.
DOI: 10.1109/JSEN.2023.3283797 | Download PDF
A Feasibility Study of Customized and Fully Aerosol-Jet-Printed Micro-Electrode Arrays for In Vitro Application
I. Armando, M. Borghetti, E. Sardini, M. Serpelloni
IEEE Sensors Journal, 23, pp. 24205–24213, 2023.
This study demonstrates the design and additive fabrication of customized microelectrode arrays using Aerosol Jet Printing, showing the potential of the technology for biomedical and in-vitro sensing platforms.
DOI: 10.1109/JSEN.2023.3313652 | Download PDF
Substrate and Coating Effects on Temperature-Related Behavior of Silver Traces Printed by Aerosol Jet for Aerospace Applications
T. Fapanni, M. Serpelloni
IEEE Transactions on Instrumentation and Measurement, 73, 2024.
This work investigates the influence of substrates and protective coatings on the temperature-dependent behavior of Aerosol Jet printed silver traces, with particular attention to demanding aerospace applications.
DOI: 10.1109/TIM.2024.3476607 | Download PDF
Preliminary Characterization of a Novel Aerosol Jet-Printed Strain Sensor for Feasibility Assessment in a Variable Stiffness Arterial Simulator Application
F. Filippi, G. Fiori, A. Genovesi, M. Barletta, M. Lancini, M. Serpelloni, A. Scorza, S.A. Sciuto
Sensors, 24, 7725, 2024.
The study characterizes an Aerosol Jet printed strain sensor and evaluates its feasibility for integration into a variable-stiffness arterial simulator.
DOI: 10.3390/s24237725 | Download PDF
Related Conference Papers
A Computational Model for the Design Optimization of Multi-Electrode Arrays by Aerosol-Jet Printing
I. Armando, M. Borghetti, E. Sardini, M. Serpelloni
Procedia CIRP, 110, pp. 87–92, 2022.
A computational approach is proposed for the design and optimization of microelectrode arrays fabricated by Aerosol Jet Printing.
DOI: 10.1016/j.procir.2022.06.018
Uncertainty Sources in Aerosol Jet Printed and Flexible Electrochemical Sensors
T. Fapanni, M. Serpelloni, E. Sardini
2022 IEEE International Workshop on Metrology for Industry 4.0 and IoT, 2022.
This contribution investigates uncertainty sources associated with the fabrication and characterization of flexible sensors produced by Aerosol Jet Printing.
DOI: 10.1109/MetroInd4.0IoT54413.2022.9831522 | Download PDF
Related Research Areas
Applications of additive manufacturing to printed resistive and capacitive sensors, flexible electronics and smart objects are presented in Printed and Flexible Electronics.
Applications involving electrochemical sensing, biosensors and ion-selective electrodes are presented in Printed Electrochemical, Biosensors and Ion-Selective Sensors.
A complete list of journal articles and conference papers is available in the Publications section.