IGF-Project 22982 N - MULTISENS - Forschungsvereinigung Räumliche Elektronische Baugruppen 3-D MID e.V.

Passive wireless read-out sensors based on additively manufactured multi-material resonant circuits [MULTISENS]

Duration: 09/01/2023 – 08/31/2025

Description

The Internet of Things (IOT), i.e. the networking of almost any physical and virtual objects, enables interaction between people and electronic systems. This is the basis for the establishment of new digital business models in many industries [1]. The resulting market already amounted to US$ 158 billion in 2021 [2]. Further strong annual growth of between 10% [3] and 20% [2] is forecast for the following years. Tapping into this market requires powerful and economical sensors. Accordingly, US$ 8.4 billion [4] will already be spent on the development and production of IOT-capable sensors in 2021. Disproportionately high growth of >25% per year [4] is forecast for this part of the value chain. Wireless sensors are of particular importance here. Such sensors combine a transducer for detecting the physical quantity with a microchip for data processing, a battery for power supply and a transmitter for wireless communication using Bluetooth, ZIGBEE or Z-WAVE [5]. These sensors are manufactured using established electronics production technologies (e.g. PCB), whereby the integration or application in the target component is usually assembly-based. Although such sensors are very powerful, there are some disadvantages:

The necessary chip and battery make integration into components more difficult, which is particularly problematic with a large number of sensors and complex-shaped components that are difficult to access.
The battery required for the energy supply requires regular maintenance and limits the service life [6]. Energy harvesting methods that could solve this problem have not yet become established.
Due to the increasing global demand for electronics technology (microchips) and unstable global supply chains, the costs for such sensors are rising, which is significantly curbing market growth [2].
The technologies used in electronics production require very large quantities for high cost-effectiveness, which leads to economic disadvantages, especially for small quantities.

The use of radio frequency identification (RFID) technologies offers the potential to overcome these disadvantages [7]. Communication and energy supply take place via inductive coupling, which makes a battery superfluous [8]. In addition, a completely passive chipless design is possible [6]. The information to be transmitted is then only encoded in the electrical properties (capacitance, inductance, resistance) of the passive electrical components used.

This makes the cost-intensive use of active microelectronic components obsolete and opens up the possibility of manufacturing sensors entirely using printing technology and without any assembly work. This results in sensor structures that are easy to integrate and can also be produced economically in small quantities using digital drop-on-demand printing processes. Depending on the application scenario, such sensor tags can be applied to films or directly to components [9].

Figure 1: Applications of printed electronics (left) [10] and volume and growth of the global market for printed electronics (right) [11]

The market for printed electronics is also currently developing rapidly. Printing technologies are used in the production of smart labels, electronics-integrated smart packaging, flexible displays and wearable electronics for the IoT, smart home and smart devices, e.g. in the environmental sector, healthcare and the food and automotive industries [10], [11] (see Figure 1). The driving force behind this development is the increasing demand for miniaturized electronics and the need for portable Internet-of-Things (IOT)-capable devices. Flexibility, cost efficiency and low manufacturing complexity are further advantages of printed electronics [10]. Accordingly, the global market for printed electronics is expected to grow from USD 9.9 billion in 2021 to USD 23 billion by 2026. This corresponds to a more than doubling of demand within 5 years (18.3% p.a., Figure 1) [11]. For the 3D-printed electronics segment, even more dynamic growth of 39.50 % p.a. is expected.
growth of 39.50 % p.a. (2019 – 2029) [12] is forecast. MultiSens is addressing these two dynamic markets and is pursuing the goal of developing fully printable passive LC sensors:

To create basic knowledge regarding the design, performance and production of a new class of passive chipless, fully printable RFID sensors,
to provide sensor users with a technology that enables the integration of sensors at significantly lower cost, more flexibly and with less space and weight requirements, and
to open up a new, highly innovative field of application for companies along the value chain of printed electronics (material components/systems printing technologies) and thus generate new market opportunities.

Economic significance of targeted research results for SMEs

The ability to achieve greater customer benefit by integrating sensor technology into products has become a competitive factor in many industries.

In discussions with potential users in the PA, the needs summarized in Table 1 with regard to wireless sensor technology have already been identified:

Table 1: Demand for wireless sensor solutions discussed with PA members; Source: Fraunhofer-Institut für Werkzeugmaschinen und Umformtechnik (IWU); Helmholtz-Zentrum Dresden-Rossendorf (HZDR)

Neben der technischen Leistungsfähigkeit ist dabei vor allem eine hohe Wirtschaftlichkeit hinsichtlich der Kosten der Sensorik sowie deren Integration notwendig. Vor diesem Hintergrund fokussiert MultiSens mit chiplosen und passiven RFID-Sensoren eine Basistechnologie, die in vielen Produkten eingesetzt werden kann. Die wirtschaftlichen Potentiale ergeben sich insbesondere aus folgenden Aspekten:

Durch den Verzicht auf aktive elektronische Bauteile und Batterien sind die Sensoren deutlich einfacher aufgebaut und preiswerter als konventionelle drahtlose Sensoren. Zudem sind sie wartungsfrei und auch unter anspruchsvollen Umgebungsbedingungen robust.
Der einfache Aufbau ermöglicht eine sehr kosteneffiziente drucktechnische Fertigung. Hierbei können sowohl maskenbasierte Verfahren wie Siebdruck (hohe Produktivität bei hohen Stückzahlen) als auch maskenlose Verfahren wie z.B. Piezo-Jet (hohe Flexibilität bei kleinen Stückzahlen) zum Einsatz kommen.
Die drucktechnische Fertigung ermöglicht eine deutlich kostengünstigere Integration. Auf Folien gedruckte Sensoren können einfach in Kunststoffbauteile integriert werden (Hinterspritzen, Kleben, Laminieren). Auch das Drucken der Sensorik direkt auf das Bauteil (z.B. mittels Piezo-Jet) stellt eine wirtschaftlich interessante Technologieoption dar.

Diese Vorteile machen gedruckte chiplose RFID-Sensoren für eine große Bandbreite an Unternehmen entlang der Wertschöpfungskette des Funktionsdruckes interessant, was sich in der vielfältigen Zusammensetzung des PA widerspiegelt (siehe Abbildung 2).

Figure 2: Composition and interaction of the PA; Source: Fraunhofer-Institut für Werkzeugmaschinen und Umformtechnik (IWU); Helmholtz-Zentrum Dresden-Rossendorf (HZDR)

The technical objective is based on the multi-material processing of optimized materials (permeability, conductivity, permittivity) with modern printing technologies. Manufacturers of functional fluids (pastes and inks) (NaPaGen, GSB Wahl, Octopus) gain knowledge about the suitability and necessary adjustments of pastes and inks and subsequently offer optimized pastes. Companies such as Suragus, Vermes, NeoTechAMT, Sintertechnik, GESIM and Sitec develop components and systems for printing production that are adapted to processing methods (material application, quality assurance, sintering) and benefit from the knowledge advantage and, where applicable, from the unique selling points they have developed. Manufacturers (Heinig, Freudenberg, Continental, Motherson) integrate the new pastes and any adapted components into their systems and thus expand their range of services with a technically and economically very attractive sensor technology. This makes it possible to tap into new market potential. Suppliers of electronic components or sensors such as MicroSensys, InnoMe, Dresden elektronik, SensorTechnikWiedemann, eesy Innovation or Smart Material are expanding their product portfolio to include printed sensors or are benefiting from new sales markets for components for wireless sensor integration. Potential users (Continental, Motherson, IMSgear, OttoBock, medi, EFW, CE cideon, Sintertechnik, SAFHolland, SAW Components) can quickly transfer the technology into products based on the technological findings. The economic advantages of printed sensor technology ensure that the products are highly competitive, which strengthens the market position of the companies and thus creates new sales potential. For the user SMEs (Thoenes, GuS, Scheer, Heinig, Sintertechnik, SAW Components), the resulting expertise along the value chain (material process technology, production technology, sensor technology) is particularly valuable, as it enables a technology entry with low investment costs and risk.