Emerging PE applications accelerate towards adoption
By Dr. Matt Dyson, senior technology analyst, IDTechEx, Cambridge UKElectronics Printable Electronics Electronics Printed-flexible sensors
2021 has been good for printed electronics, with multiple designs reaching commercial adoption
Printed/flexible electronics has long been touted as the technology that will make electronics ubiquitous. Promised applications include wireless sensors in packaging, skin patches that communicate with the internet, and buildings that detect leaks to enable preventative maintenance. However, until recently such applications have largely remained in the prototyping and development stages.
However, 2021 has been an exciting year for printed electronics, with multiple applications reaching commercial adoption and significant funds flowing into the sector. Even where technologies are not yet commercialized, companies are increasingly transitioning from developing their technology and producing speculative demonstration prototypes to development and qualification projects for specific customers.
Healthcare/wellness: Utilizing flexibility
Successfully commercializing printed/flexible electronics requires identifying applications where its differences from conventional electronics add significant value. Electronic skin patches are a great example of this, with flexible thin-film devices improving patient comfort while enabling continuous monitoring of biometric parameters.
Interest in electronic skin patches has really accelerated in 2021, with dedicated material portfolios being developed by major players such as Dupont and Henkel, and the patches being utilized in hospitals. This uptake in traction is partially attributed to COVID-19 since both patients and healthcare professionals are now much more comfortable with remote consultations that necessitate home monitoring. Furthermore, many healthcare systems are struggling with a backlog of patients after operations/screenings were canceled, creating an additional drive to adopt new technologies that can improve efficiency, for example by facilitating earlier discharge from hospital.
Automotive: Accompanying the transition to EVs
While the transitions towards automotive electrification and autonomy attract plenty of attention, they are accompanied by the adoption of other technologies that to some extent fall under the radar. Increasing adoption of printed electronics is one such example, with applications in both interiors and exteriors.
Interiors are especially promising targets for innovation that adds value to the occupant experience since it’s trickier for manufacturers to differentiate EVs based on the powertrain. As such there are extensive opportunities for printed/flexible electronics to add additional functionality to the cockpit while facilitating efficient manufacturing. Examples include adding more and higher performance displays and capacitive control surfaces. Indeed, backlit capacitive touch sensors comprising inlayed transparent printed metal mesh films and thermoformed parts, developed by PolyIC, have been commercialized in Volkswagen models launched in 2021.
There is also growing interest in heaters for automotive applications since EVs generate far less residual heat. While printed electronics are already used for some seat heaters, implementing heaters made from either resistive or positive temperature co-efficient conductive inks into surfaces would improve heating efficiency and hence slightly extend EV range. Transparent heaters, which can be made from either metal mesh, carbon nanotubes (CNTS), or silver nanowires, are also being developed and trialed, with initial target applications being headlight and sensor covers.
Smart packaging: Technical innovations boost feasibility
Smart packaging has received a significant boost towards widespread adoption in 2021, with two emerging players raising $10s of millions in funding to scale up production and extend their technical capabilities.
Defined as integrating electronic functionality such as antennas and sensors into packaging to track its progress and condition through the supply chain and into the home, smart packaging has long been touted as a promising application for printed/flexible electronics. This is because, unlike conventional rigid electronics, printed/flexible electronics is theoretically compatible with very high throughput roll-to-roll (R2R) production to enable the very low production costs required.
However, despite the widespread adoption of RFID tags, smart packaging with integrated sensing has thus far remained limited to niche applications. This is primarily because the cost targets for most smart packaging applications are extremely challenging, especially since a power source or energy harvesting capability, one or more sensors, processing IC, and an antenna all need to be incorporated. Furthermore, smart packaging generally only adds value when it facilitates an integrated solution together with the software. This usually requires entering a market at scale and being simultaneously adopted by multiple players in the supply chain.
In an attempt to reduce the cost of smart packaging hardware, thus opening up the technology to higher volume applications, innovative hardware technologies are being developed. PragmatIC, a UK-based firm that produces natively flexible metal oxide ICs, raised $80-million in Series C funding in October 2021. The key value proposition of Pragmatic’s ICs is their low cost, potentially less than 1 US cent each. While RFID is the initial application, slightly more complex ICs for sensing applications are also being developed.
Another promising innovation for smart packaging is sensors that harvest energy from ambient electromagnetic radiation. Developed by US-based Wiliot, which raised $200m in a Series C funding round, these battery-free wireless sensors communicate via Bluetooth. Event-based sensing is used to only communicate when the position of the sensor changes, and hence reduce power consumption. ICs from both PragmatIC and Wiliot will be mounted on flexible substrates, with antennas often produced from conductive inks – this emerging manufacturing methodology that combines printing and mounting components is termed ‘Flexible Hybrid Electronics (FHE)’.
With this incoming investment facilitating growth in technologies that resolve some longstanding pain-points, 2021 could turn out to be there year that kickstarts the adoption of smart packaging.
Smart buildings and IoT: Combining sensing and energy harvesting
IoT devices, defined here as a network of wirelessly connected sensors for both domestic and industrial applications, offer benefits such as predictive maintenance and condition monitoring. They represent a great opportunity for printed/flexible electronics since they need to be affordable and have a compact form factor to fit into buildings, industrial equipment, etc.
Despite the clear value proposition, powering IoT devices remains a challenge since replacing batteries is both wasteful and expensive when the maintenance time is included. An emerging candidate to resolve this issue is organic photovoltaics (OPV). While the large-scale adoption of organic photovoltaics has previously proved challenging, the energy harvesting technology is extremely well suited to indoor energy harvesting since it is more efficient than silicon photovoltaics under low-intensity diffuse radiation. The films are also cheap to produce via solution processing, while their flexible, thin film form factor improves durability and integration possibilities.
Indoor OPV cells for low-power IoT devices is being developed by companies such as Epishine, Dracula Technologies, and Ribes Tech. This technology gained traction in 2021, with Epishine’s OPV cells installed in commercially available facilities management products.
Other applications of printed/flexible electronics for printed electronics in smart buildings take advantage of the ability to produce relatively simple large area devices at an accessible price point. Applications include heating and leak detection, either integrated into building materials or retrofitted. In 2021, early-stage UK firm Bare Conductive launched Laiier, targeting these applications – low-cost leak detection is proving especially compelling to the insurance industry, with multiple projects in development.
The year ahead
This commercialization of printed/flexible electronics is expected to continue in 2022 across all the technologies and applications outlined above, with capacitive touch sensors made from printed metal mesh, OPV cells for indoor energy harvesting, and increasingly flexible electronic skin patches all gaining traction.