The sensor market is one of the most promising for flexible and printed electronics. In particular, automotive and healthcare are ideal markets for flexible sensors. A number of companies are already having success in these fields.

John Berron, principal business development engineer for Brewer Science, said that flexible and printed sensors are the future.

“This is where Brewer Science operates,” added Berron. “Our customers continue to require more and more sophisticated solutions and the actionable data generated by them.”

“As devices get smaller and more compact, the need for compression force sensing in limited space is increasing. Flexible, printed sensors are a key towards accomplishing this,” said Ed Haidar, product manager for the Embedded Sensing Division and an applications engineer with Tekscan.

Flexible sensors are enjoying opportunities in a wide range of markets, including automotive, health care, environmental and others.

“Brewer Science has seen steady interest across all of the market areas you mentioned,” said Berron. “The need for better and better data solutions in each seems to be the revealing trend. Our most recent focus areas have been in the industrial and environmental markets.”

Canatu Oy has been mass manufacturing CNB sensors for an electric vehicle since 2015, and will be making new announcements in this area soon. Ilkka Varjos, CTO, Canatu Oy, said that Canatu is seeing opportunities for flexible and printed sensors, especially in automotive ADAS heaters, touch sensors and medical diagnostics.

“Initially we have mainly focused on automotive ADAS heater and touch applications, but due to unique properties of CNB we also see great potential in healthcare and beyond,” added Varjos. “Recently, our team has focused on developing transparent film heaters for ADAS camera and LiDAR sensors to enable any-weather safe autonomous driving. The number of vehicles with active safety applications is rapidly increasing, yet reliability in harsh weather remains among the greatest constraints to ADAS uptake. Camera sensors get blocked by rain, snow or ice obstructing the system view, thereby making accurate object detection more difficult. In sub-optimal weather the effective LiDAR measurement range may decrease. While conventional metallic wire heaters cause image distortion on camera view, and disturb LiDAR measurement range accuracy, CNB film heaters provide even heating and low distortion, enabling flawless operation of camera and LiDAR systems.

“In medical diagnostics, Canatu participates in a new Finnish ecosystem developing rapid and highly sensitive diagnostics tools to overcome future pandemics and other diverse diagnostic challenges of tomorrow. Within this program, Canatu will develop a hybrid sensor which can do two things: to detect the target and measure drug concentration,” Varjos noted.

In addition, Varjos noted that within the Fast Electrochemical Point-Of-Care Diagnostics project, Canatu has developed CNB electrochemical sensors for real-time detection of analgesics in blood, saliva and urine, which is now being evaluated with clinical samples from the Helsinki University Hospital. Clinical studies began in July 2020 and were estimated to last until June 2021.

“Overall, our strategic R&D programs are focused on improving CNB performance, which will expand application opportunities for CNB,” Varjos concluded. “We are also actively screening new applications where we could add more value with our material. One of these areas is semiconductor manufacturing. In EUV applications, our free-standing CNB membrane provides unique benefits due to high transmittance, thin yet durable structure capable of filtering particles down to nanoscale and high heat resistance to withstand the extreme physics.”

Haidar said that automotive, health care and environmental sensors are all key opportunities.

“All of those markets are promising end users, but truthfully, there really are no limits when it comes to applications for printed sensors and electronics,” added Haidar. “The core technology is very versatile. The focus these days is on making sensor technologies that are more flexible and stretchable that can also function in harsh environments (high temperature, high humidity, etc.). What separates one sensor supplier from another really comes down to setting the engineer up for success for their unique application. This includes the availability of integration tools, resources and applications engineering assistance that can help the engineer stay successful through all phases of their design.”

Berron noted that there are new opportunities for flexible sensors.

“Brewer Science has been hard at work developing our newest line of printed sensor and smart devices to be used in the environmental space, more specifically within the area of water quality detection,” Berron noted.

“Our sensors and FHE elements are just as likely to go into a finished product as they are likely to go into a manufacturing process, testing equipment or a maintenance tool,” Berron added. “An example of this is highlighted for one of our customers at the end of 2020. As their production ramped to 10 million for their newest product, a faster method to test and calibrate at the end of assembly became essential. Our team was able to develop a device with a printed section to test and calibrate the machines. This proved to be much faster and transferable across their production facilities and lines.”

“We are adding to our standard product portfolio to address the ever-evolving needs of our market,” said Haidar. “This includes a high-demand sensor form factor with operational capabilities that can withstand rigorous operating environments.”

There is a lot of work being done on creating flexible electronics products that can be recycled or reused.

Tekscan’s Haidar noted that many sensors have withstood several million actuations in rigorous applications with minimal change to the sensor’s sensitivity or performance.

“So many of the products that incorporate our sensors have a long life cycle, especially when certain design considerations are made to product and extend the life of the sensor,” added Haidar. “Even so, we’re always researching new materials and force-sensitive ink formulations to help extend the life of our sensors in a variety of applications. A major part of this is implementing measures for recycling and salvaging raw materials, tooling, and equipment whenever possible.”

Berron reported that sustainability is a constant consideration and focus for Brewer Science.

“Increasingly our customers are asking us to incorporate additional environmental requirements and capacities,” Berron said. “One such project has seen our focus on plug-and-play sensors. This capability lends itself to being able to exchange just the printed component or sensor with a new one. This allows for the item to be returned or recycled, thereby minimizing both waste and downtime.”

“As a part of our new sustainability strategy, Canatu will explore the availability of bio-based materials during this year,” Varjos said. “Overall, in our view COVID-19 has accelerated the transition to a sustainable automotive industry and customers are increasingly opting for more sustainable materials and products.”

There are challenges ahead for commercialization of flexible sensors, and industry leaders offered ideas on how these challenges can best be overcome.

“The biggest challenge we see for commercialization of printed electronics and sensors is that the industry is still just beginning to recognize what is available and is still cautious to adopt,” Berron said. “Before there is a willingness to embrace the technology there must first be both the confidence as well as the cost. For both of these reasons it makes sense that not every solution needs to yet be entirely printed.”

“One of the biggest challenges to commercialization of flexible sensors is the nuances involved in their technical integration,” said Haidar. “Teaming up with a supplier with a proven track record for helping customers be successful with their sensor-integration process will ensure the end user has access to the support needed to efficiently complete their integration and bring their product to market.

“At Tekscan, we have prioritized applications engineering and passed our experience and expertise to our customers, allowing them to anticipate potential design challenges and navigate their transfer to production with the confidence required in a high-volume production environment,” Haidar concluded.