Patent Title: Polymer-Based Ink Compositions for Use in the Production of Piezoresistive Films
IP Status: Published international patent application; filing/protection coverage in Türkiye and the European Patent route.
Technology Area: Structural Health Monitoring / Piezoresistive Sensors / Functional Inks / Graphene-Based Composites
TRL: TRL 5
This polymer-based piezoresistive ink forms films or sensor strips whose electrical resistance changes under mechanical strain. Applicable to surfaces including concrete, wood and plastics, the technology provides an adaptable platform for monitoring deformation, accumulated structural damage and mechanical interaction across infrastructure, composites, vehicles and robotic systems.
Technology Overview
The technology is a polymer-based ink composition for producing piezoresistive films whose electrical resistance changes in response to mechanical loading or deformation. The ink contains graphene nanoplatelets and graphite powder dispersed within an aqueous polymer matrix. Once applied to a surface and formed into a film, mechanical strain changes the conductive network within the material, allowing deformation to be monitored through electrical-resistance measurements.
Within the material architecture, graphene nanoplatelets contribute to the formation of electrically conductive pathways, while graphite particles provide a supporting framework for these conduction networks. Combining the two carbon-based components enables the formulation to balance film-forming behaviour with electrical and mechanical performance. Patent testing demonstrated that selected compositions maintained their piezoresistive sensitivity during repeated deformation and produced stable conductivity responses for at least 30 loading cycles under the same deformation conditions.
The ink can be deposited using techniques including screen printing and spraying. This processing flexibility allows the sensor to be formed directly on the structure or component being monitored rather than being restricted to a separately manufactured electronic sensor. Laboratory-scale applications have been performed on concrete, wood and plastic substrates, including tests on actual cement-based surfaces. Electrically conductive substrates such as metals require an insulating layer between the sensor and the underlying surface.
The polymer matrix can be adapted using different polymer systems. In addition to polyvinyl alcohol, the patent describes options including PVDF, PLA, PANI, PMMA, PEG, PET and TPU. This provides a material platform that may be tailored not only to rigid structural surfaces but also to flexible or moving systems where piezoresistive sensing is required.
Because the sensing material is supplied as an ink, sensor geometry can be adapted to the target surface and distributed sensing patterns can be created over selected areas. This enables applications ranging from monitoring deformation in buildings and infrastructure to tracking critical regions in composite structures, detecting damage or intervention on vehicle body and chassis components, and providing touch or load sensitivity on robotic surfaces.
Problem / Market Need
Buildings, bridges, composite structures, vehicles and industrial systems experience repeated loading, vibration, mechanical strain and environmental exposure throughout their service lives. Detecting deformation and damage as they develop is important for maintenance planning, safety assessment and reducing the risk of unexpected structural failure.
Conventional point sensors can require numerous individual devices, wiring and installation operations when large or geometrically complex surfaces need to be monitored. Integrating prefabricated sensors onto existing structures or irregular surfaces can also limit placement and sensing coverage.
A polymer-based piezoresistive ink allows the sensing function to be formed directly on the surface being monitored. Sensor strips or films can therefore be designed for different geometries, enabling adaptable and potentially distributed systems for electrically tracking strain, mechanical interaction and structural change.
Key Advantages
- Piezoresistive sensing of mechanical strain and deformation through measurable resistance changes
- Conductive network architecture combining graphene nanoplatelets and graphite
- Patent testing demonstrated retained piezoresistive response for at least 30 repeated deformation cycles
- Can be applied as an ink, film or sensor strip in application-specific geometries
- Compatible with surface-deposition methods including screen printing and spraying
- Demonstrated applicability to different substrates including concrete, wood and plastics
- Potential adaptation to rough surfaces and substrates with different surface chemistries
- Versatile sensing platform spanning structural health monitoring, movement sensing and robotic touch applications
Applications
- Structural health monitoring of buildings and bridges
- Strain and deformation monitoring on concrete and cement-based structures
- Monitoring critical joints and damage zones in composite structures
- Damage or intervention detection on vehicle body panels and chassis structures
- Detection of deformation or impact-related damage in transport and cargo packaging
- Cyclic-load and fatigue monitoring in industrial equipment
- Surface touch and pressure sensing for robotic systems
- Flexible sensors for wearable and motion-monitoring applications
- Surface-applied sensors operating under varying temperature conditions
Relevant Industries
- Construction and Infrastructure
- Structural Health Monitoring
- Automotive
- Aerospace and Composite Structures
- Robotics and Automation
- Smart Sensors and Electronics
- Logistics and Smart Packaging
- Technical Textiles and Wearable Technologies
Technology Readiness Level & Validation
Technology Readiness Level: TRL 5
A laboratory-scale prototype has been developed and testing has begun using both ink and strip/film formats. The piezoresistive material has been applied to concrete, wood and plastic surfaces, including evaluation on actual cement-based substrates. Resistance changes under mechanical strain have been demonstrated as a measurable sensing output.
Testing and validation are continuing under different loading conditions and with different substrate materials. In deformation testing disclosed for the patented material, the piezoresistive films retained their sensitivity through at least 30 successive deformation cycles and provided a stable electrical response under repeated loading conditions.
Laboratory studies have also examined the sensor structure across temperatures from -10 °C to 80 °C. These tests contribute to evaluating its potential for operation under varying environmental conditions but do not constitute final field durability validation or product certification.
Because metallic substrates are electrically conductive, use on these surfaces requires an appropriate insulating layer between the sensing film and the underlying material. Direct validation on metallic substrates has not yet been completed.
The technology was developed within a TÜBİTAK 1001 research project.
Intellectual Property
International Patent Publication: WO2025085024A2
International Application No.: PCT/TR2024/051020
Turkish Application: TR2023/013224
Patent Title: Polymer-Based Ink Compositions for Use in the Production of Piezoresistive Films
Priority Date: 17 October 2023
International Filing Date: 4 September 2024
International Publication Date: 24 April 2025
Applicant: Sabancı University
Protection / Filing Coverage: Türkiye, European Patent route
Commercialisation Status
A laboratory-scale prototype is available and the technology is available for licensing. Ongoing development focuses on validating sensor performance across different substrate materials, environmental conditions and target applications.
Collaboration Opportunities
- Licensing
- Scientific consultancy
- Joint R&D and co-development
- Industrial validation and pilot testing
Potential partners may include structural-health-monitoring solution providers, sensor and electronics manufacturers, construction and infrastructure companies, automotive and composite manufacturers, robotics developers, and organisations working on surface-applied functional materials.
Promising areas for joint development include distributed sensor networks for large surfaces, long-term monitoring of loading and damage under field conditions, insulated sensing architectures for metallic substrates, and application-specific pilots in infrastructure, automotive and robotic systems.
Inventors
Inventors: Mehmet Ali Gülgün, Melike Nur Önder, Melih Papila
Contact
For licensing, industrial validation, joint R&D or other collaboration opportunities related to this technology, please contact Sabancı University Technology Transfer Office (SUATT) at dpe.suatt@sabanciuniv.edu.