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2021
Report
Titel
Digital Manufacturing Technologies for the Development of Smart Sensors and Electronics for Agro-Industrial systems
Titel Supplements
Research and development report of the MANUNET ERA-NET collaboration project "DigiMan"; Project duration: 01.12.2017 - 30.11.2020
Abstract
The DigiMan project developed innovative sensor platforms for agro-industrial applications by providing a digital manufacturing process chain based on printing technologies and nanomaterial inks. This makes it possible to miniaturize the sensors, to achieve a flexibility in the target sensor properties and to realize these sensors in economically low cost even for small sensor batch quantities. The project utilized digital technologies for the sensors manufacturing, illustrating the benefits of a 3-D prototype philosophy (rapid, simple and cost effective). Environmentally friendly digital additive printing technologies like inkjet or aerosol-jet as well as drop-coating and laser machining made it possible to miniaturize the sensors sizes, along with a reduction in needed sensor power consumption. The applied technologies allow the customization of sensor properties and to realize this economically even for small sensor batch quantities. The equipment involved does not need expensive clean-rooms or vacuum technologies and is already introduced in the market. The software for digital design of manufacturing this sensor platforms is simple and has open access or free distribution on student level, which makes a significant contribution to the dissemination of the developed technologies and materials among future engineers by a reduced ""price of entrance"". Material developments lead to the application of self-synthesized silver, copper and platinum nanoparticle inks, which are compatible to inkjet and aerosol-jet printing (particle size control < 200 nm, variation of ink solid content up to 50 wt.-%, good sedimentation stability achieved). These were used for the resource-efficient printing of miniaturized heaters, antennas for wireless data transmission and functional sensor layers to detect humidity and temperature. The first sensor platform comprised a metal-oxide semiconductor gas sensor (MOX, ceramic MEMS) printed on a newly developed very thin (20 to 40 mm) and mechanically flexible yttria stabilized zirconia membrane. A direct printed miniaturized platinum heater (40 mm line width, up to 500 °C local temperature) led to a very low power consumption (< 200 mW), which is highly attractive for gas sensing applications. The thin zirconia membrane is compatible to laser processing and ceramic pack-aging technologies, which have potential to obviate some difficulties associated with traditional packaging technologies (integration of filters, printing antennas, holes for gas access to sensors). This approach can become an attractive alternative for small-scale integration of sensor components. For the gas sensing electrode, special metal oxide inks for sensing methane, hydrogen, carbon monoxide and ammonia were developed. The second sensor platform comprised digital printed humidity (25 to 75 % RH) and temperature sensors (10 to 90 °C) on low-cost PET polymer and paper foils. The inkjet printing method was scaled from sheet-to-sheet to a roll-to-roll manufacturing (R2R). A developed low energy Bluetooth sensor platform with silver inkjet printed antenna demonstrated the wireless communication of the developed sensors within a 50 m radius. An additionally printed RFID NFC communication tag can digitally label individual sensors. Both developed sensor platforms were tested under agro-industrial relevant parameters, especially in a wide spectrum of temperatures and humidity ranges as well as in the presence of agro-industrial gases.
Author(s)
Verlag
Fraunhofer IKTS
Verlagsort
Dresden