The Geometry Problem That Rigid Electronics Cannot Solve
Industrial condition monitoring uses sensors to measure the physical state of machinery, structures, and processes whose operational health determines the maintenance decision and the production reliability that industrial operations management targets. The accelerometers, temperature sensors, strain gauges, and acoustic emission sensors that conventional condition monitoring deploys are manufactured as rigid electronic components on inflexible printed circuit board substrates whose geometry constrains their installation to the flat, accessible surfaces that rigid sensor packages can be attached to. The curved, complex, or confined geometries of the structural and mechanical components that condition monitoring is most commercially valuable for, including turbine blades, pipeline welds, aircraft composite skin panels, rotating shafts, and the interior surfaces of tanks and vessels, either cannot accommodate rigid sensor installation or require the machining of sensor housings and cable routing provisions whose engineering cost exceeds the monitoring value they enable.
Printed and flexible sensors address the geometric constraint of rigid electronics by manufacturing the sensing element and its associated signal processing circuitry on thin flexible substrates, typically polyimide, PET, or fabric, using printing or coating processes that deposit functional electronic inks whose conductivity, piezoelectricity, capacitance, or other sensing properties create the required measurement function in a form that conforms to the curved or irregular surface geometry of the component being monitored. A flexible strain sensor printed onto a thin polyimide film can be adhered to the curved surface of a pressure vessel, a pipe elbow, or a composite aircraft panel using standard adhesive bonding, measuring the surface strain that indicates stress concentration, fatigue crack propagation, or wall thickness loss from corrosion at a spatial resolution and coverage area that an array of discrete rigid strain gauges would require dozens of individual instruments and extensive surface preparation to achieve.
Aerospace Structural Health Monitoring
The aerospace structural health monitoring application of flexible sensors is the use case whose technical requirements are most demanding and whose commercial value per installation is highest. A commercial aircraft whose airframe develops a fatigue crack that conventional maintenance inspection detects only at the scheduled inspection interval may remain in service with an undetected crack for hundreds of flight hours before the next inspection, creating the structural risk that the aviation safety record has historically managed through conservative inspection intervals whose frequency adds maintenance cost and aircraft ground time. A flexible sensor network whose piezoelectric elements bonded to the composite skin panels and metal structural members of the aircraft generate and receive ultrasonic Lamb waves whose propagation changes in the presence of delamination, cracking, or impact damage could provide the continuous structural health monitoring that replaces periodic manual inspection with real-time damage detection, enabling the condition-based maintenance scheduling that reduces both maintenance cost and structural safety risk simultaneously.
Brewer Science, a US materials company with a printed electronics heritage, has developed flexible sensor systems for aerospace structural health monitoring whose thin film piezoelectric sensor arrays adhere directly to composite and metal aircraft surfaces. Its work with the US Air Force Research Laboratory and NASA on flexible structural health monitoring sensor integration in composite aircraft structures has demonstrated the installation feasibility and sensing performance that aerospace qualification requires as a prerequisite to the airworthiness certification that commercial aircraft structural monitoring applications must achieve. The PARC research centre, now part of SRI International, has developed printed electronics manufacturing processes for flexible sensor arrays whose combination of roll-to-roll printing scale and aerospace-grade sensor performance creates the manufacturing approach that large-area flexible sensor coverage of aircraft structures requires at costs that the aviation maintenance economics can support.
Pipeline and Infrastructure Monitoring
The oil and gas pipeline industry's corrosion and integrity monitoring requirement creates the most commercially urgent application for flexible sensors in industrial condition monitoring. A flexible sensor array bonded circumferentially around a pipeline weld or a corrosion-susceptible pipe segment provides the continuous measurement of pipe wall thickness, strain distribution, and crack propagation that point measurements from discrete sensors cannot provide without complete coverage. The pipeline length that requires monitoring, measured in hundreds of thousands of kilometres globally, and the consequence of undetected corrosion or cracking in terms of environmental damage, production loss, and regulatory liability create the commercial case for flexible sensor coverage at costs per monitored metre that the scale of the monitoring challenge requires to be substantially lower than discrete sensor installation at equivalent coverage density.
Top 10 Companies in Printed and Flexible Sensors Globally
- Brewer Science: US printed electronics company with flexible piezoelectric and strain sensor systems for aerospace and industrial structural health monitoring; its aerospace research programmes with USAF and NASA and its flexible sensor manufacturing capability create the commercial pathway from laboratory demonstration to airworthiness-certified structural monitoring product.
- SRI International (PARC): US research organisation with printed electronics manufacturing processes for large-area flexible sensor arrays; its roll-to-roll printing capability and its aerospace and industrial sensor application research create the manufacturing technology foundation that commercial flexible sensor production at scale requires.
- Tekscan: US flexible pressure sensor company with tactile and force measurement systems for industrial, medical, and research applications; its thin-film piezoresistive sensor technology and its commercial distribution across industrial and medical measurement applications create the most commercially established flexible sensor business whose product range demonstrates the application breadth that flexible sensor technology enables.
- Piezo Systems (TE Connectivity): US piezoelectric film sensor manufacturer with PVDF flexible piezoelectric sensors for structural monitoring, vibration measurement, and acoustic emission detection; its PVDF film product range and its integration within TE Connectivity's industrial sensor portfolio create the commercial piezoelectric flexible sensor product whose industrial market distribution TE Connectivity's global sales channels enable.
- Sensitronics: US flexible force and pressure sensor company with custom sensor array design for industrial condition monitoring, robotics, and automotive applications; its flexible resistive sensor array manufacturing and its custom sensor geometry capability create the application-specific flexible sensor product that industrial monitoring installations whose non-standard surface geometries require.
- Nanoleaf Technologies: Flexible sensor and electronics company with printed sensor arrays for smart textile and industrial monitoring; its textile-compatible printed sensor technology creates the wearable and conformal sensor application for industrial condition monitoring in manufacturing environments where garment-integrated sensing monitors worker safety and ergonomic stress.
- StretchSense: New Zealand flexible and stretchable sensor company with capacitive soft sensors for robotics, motion capture, and industrial automation; its stretchable sensor technology that maintains electrical performance under large deformation creates the sensor capability for applications on surfaces whose operational movement would destroy conventional flexible sensors.
- Hamlin Electronics (TE Connectivity): Flexible and thin-film sensor manufacturer with magnetic and proximity sensing applications for industrial and automotive monitoring; its flexible thin-film sensor integration in constrained installation spaces and its automotive-qualified sensor products create the commercial flexible sensor position in the vehicle electrification and manufacturing automation markets.
- Xerox PARC Spin-offs: Multiple commercial companies emerging from the PARC printed electronics research programme whose technologies include flexible sensor manufacturing processes for industrial and medical applications; the commercial spin-out model from PARC's research creates the technology transfer pathway from advanced printed electronics research to commercial flexible sensor products.
- Tactotek: Finnish in-mold electronics company with printed flexible electronics integrated directly into three-dimensional plastic components; its IMSE technology that embeds flexible printed circuits and sensors within injection-moulded plastic parts during the moulding process creates the integrated structural sensor product for industrial and automotive applications whose sensor is part of the structure rather than attached to its surface.