Printed and flexible sensor market grows

Something that may seem very technological, restricted to medical and industrial environments, is much closer to us than we realize. We’re talking about sensors that measure various quantities, such as temperature and humidity. One of the classes of this technology is printed sensors, produced on flexible substrates, whose market is expected to reach US$ 960 million by 2034, according to a recent report by  IDTechEx.

Being able to measure a multitude of properties, such as touch, force, pressure, displacement, electrical signals and gas concentration, these sensors have an application very close to us – they are used in cars to detect seat occupancy. However, they can also be seen in areas such as healthcare, consumer electronics, logistics and wearables.

Conventional electronics manufacturing, in which a copper laminate is etched onto a printed circuit board, is a well-established technology. So why adopt flexible printed electronics? According to IDTechEx, the main benefits are the possibility of having a flexible and potentially extensible format and the ability to produce large areas. “In the case of printed circuit boards using copper laminate, components are often assembled into ‘rigid islands’ using standard sheet-to-sheet methods,” the report details.

IDTechEx predicts that while printed and flexible sensors that measure force will continue to dominate the revenue share, other applications should see increasing adoption. For example, printed sensors are being adopted in consumer electronics devices such as laptops and power tools. In the automotive sector, they are helping with battery monitoring and the human-machine interface. And in the health sector, the flexibility and elasticity of flexible printed sensors make them interesting for use in pressure-sensitive insoles that monitor gait, for example. “Hybrid printed model technologies represent a new breakthrough in the current sensor sector and should drive totally innovative use cases,” says the IDTechEx report.

The IDTechEx study evaluated eight printed sensor technologies: piezoresistive printed sensors and force sensors, piezoelectric sensors, photodetectors, temperature sensors, strain sensors, gas sensors, capacitive touch sensors and wearable electrodes. The report also discussed areas of innovation in the manufacture of printed sensors, such as emerging materials and the technology underlying manufacturing processes. In addition, the document contains forecasts of the market for printed and flexible sensors over 10 years.

Advantages also in manufacturing processes

In addition to new application possibilities, printed and flexible sensors offer advantages when it comes to the manufacturing approach. By replacing the subtractive removal of plated copper with the additive deposition of conductive ink, you can reduce waste and facilitate manufacturing with rapid prototyping and simple design adjustments.

The IDTechEx report also evaluates a series of manufacturing innovations and their prospects, ranging from fully additive 3D electronics to molded electronics and new digital printing methods.

In the field of materials, printed and flexible sensors use conductive inks with various compositions and attributes. Viscous ink based on silver flakes for screen printing dominates, but alternatives such as nanoparticle and particle-free inks are gaining traction for specific applications, such as EMI shielding against electromagnetic interference. According to IDTechEx, a notable trend is the development of copper inks, which promise much lower costs compared to their silver counterparts. Technical advances have been able to largely solve problems with oxidation, thus bringing copper inks very close to commercial use.

Other materials have contributed to the viability of printed and flexible sensors. For example, ultra-low temperature solder and field-aligned anisotropic conductive adhesives allow components such as LEDs to be securely attached to cheaper, thermally fragile substrates. In addition, printable piezoelectric polymers help with vibration detection, and functionalized carbon nanotubes with ion detection.