Self-disinfecting, smart microfilms for healthcare & community acquired infections

Project Information

SafeTouch

Grant agreement ID: 101185759

DOI

10.3030/101185759

EC signature date 19 February 2025

Start date 1 January 2025

End date 30 April 2028

Funded under

• The European Innovation Council (EIC)

Total cost

€ 2 982 936,25

EU contribution

€ 2 982 936,25

Coordinated by

ETHNICON METSOVION POLYTECHNION
Greece

Periodic Reporting for period 1 - SafeTouch (Self-disinfecting, smart microfilms for healthcare & community acquired infections)

Reporting period: 2025-01-01 to 2026-04-30

Summary of the context and overall objectives of the project

High-touch surfaces in healthcare and public environments act as fomites, enabling indirect pathogen transmission, and in hospitals the gap between manual chemical disinfection cycles creates a window in which bacteria and viruses can persist, accumulate, and spread. More than 4 million patients acquire a healthcare-associated infection each year in European hospitals, causing approximately 40,000 deaths and over €7 billion in direct medical costs, which underscores the need for autonomous, continuous, chemical-free surface disinfection. SafeTouch addresses this need through a novel intelligent microfilm, iST, that can be applied to existing high-touch surfaces or integrated into new products. Using a controlled subsecond heat pulse, it inactivates over 99% of pathogens while staying below the threshold for human skin injury, providing on-demand disinfection that is both effective and safe to touch. The project is also advancing knowledge in flexible microelectronics, thermal biosafety, and IoT-integrated smart surfaces, positioning European SMEs and research institutions at the forefront of a growing global hygiene technology market. In parallel, it integrates social sciences and humanities expertise to assess social impact and acceptability, including user experience in real-world deployment, technology acceptance among healthcare workers, patients, and senior care residents, and human-centred design principles. By addressing trust, usability, and behaviour from the outset, SafeTouch aims to ensure the final proofs of concept are effective, safe, trusted, and easy to use.

Till end of project, we are:
- Designing & fabricating the iST microfilm on flexible and rigid glass substrates, including embedded temperature sensors (WP1, WP3).
- Validating antimicrobial efficacy and biosafety in laboratory settings, including cytocompatibility and skin contact models (WP2).
- Building functional proof-of-concepts, including a smart door handle and a light switch, for testing in real healthcare and senior care environments (WP3).
- Applying the European Commission’s Safe and Sustainable by Design (SSbD) framework from the start to assess every chemical and material (WP4).
- Creating a route to market through IP protection, standardization, and a business model that positions EU manufacturers as leaders in active hygiene surfaces (WP5).

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In the first 16 months, we successfully transitioned the intelligent Surface Thermal (iST) microfilm concept from theoretical simulation to functional microchip samples :

WP1: Development of iST Microfilms (Led by NTUA, FHG)
A transient 2D finite element model was used to optimise the SU8/metal/glass microheater, evaluating 800 design scenarios and selecting six near-optimal options. The best design achieved 11.89 J/cm² energy density, a 297 ms rise time, and only a 2 K temperature variation at 473 K, confirming sub-second activation and high temperature uniformity. A full cleanroom fabrication process was established for flexible iST chips, including metallization, photolithography, etching, and SU-8 structuring, alongside chemical strengthening of 100 µm glass enabling bending to a 20 mm diameter and successful assembly of first wire-bonded chips on PCB carriers. Thermo-electrical characterisation defined the microheater TCR and supported development of a portable closed-loop activation unit with precise temperature control and non-contact finger detection. The chip exceeded 150°C within 100 ms, meeting requirements for the door-handle proof-of-concept, and demonstrated stability over more than 8,000 thermal cycles. A multilayer thermal model further assessed burn risk, defining safe operating windows and showing that, under accidental contact conditions, residual heat transfer remains confined to the epidermis.

WP2 : Methodology Optimisation for Antimicrobial Testing:
- Systematically evaluated the originally planned touch-transfer and modified ISO 22196 methods, and identified that the iST microfilm’s hydrophobic SU8 surface and low bacterial adhesion required a revised approach.
- Compared swab-based, drop-based, and loop-assisted inoculation methods, and found that contact plate transfer is the most reliable recovery method, while liquid recovery showed higher variability. This established a reproducible baseline protocol for future efficacy testing.
- Successfully completed cytocompatibility assessment according to ISO 10993-5 using L929 fibroblast cells exposed to iST microfilm extracts prepared per ISO 10993-12, providing the first validated in vitro evidence of biocompatibility under the tested conditions and establishing a safety baseline for the final device formulation.

WP3: Proof-of-Concept Development
- Finalised a functional CAD design for a retrofittable smart door handle proof-of-concept, integrating the iST microfilm directly into the hand-contact zone.
- Developed a split-electronics architecture, positioning batteries and the Wi‑Fi controller in the rosette (wall plate) and the power amplifier in the handle to minimise cabling across the mechanical pivot.
- Implemented a modular electronic control system comprising a power management subsystem, a power delivery stage with FET driver and back-EMF protection, and a precision measurement subsystem with a 16-bit ADC, 1 mA constant current source, and 0.1°C measurement precision.
- Designed a complete ESP32-S3 firmware framework enabling fixed-duration and temperature-targeted pulse modes, cooldown protection logic, and onboard CSV data logging.
- Delivered a full API infrastructure, including a Postman collection and endpoints for device status, scheduling, & firmware updates, alongside a cross-platform web application for remote device management, real-time monitoring, & schedule programming.

WP4: Safe & Sustainable by Design, SSbD Step 1 & 2 Implementation:
- Completed Step 1 of the EC’s SSbD framework, identifying and categorising 30 chemicals used in the iST manufacturing process according to hazard profiles.
- Critical Safety Outcome: Two substances (2-methoxypropyl acetate and tetramethylammonium hydroxide) were classified as Level 0 (requires immediate substitution). Seven substances as Level 1, fifteen as Level 2, and six as Level 3. FHG was notified and has already initiated substitution plans, aligning with the project’s safe-by-design principles. Life Cycle Assessment (LCA) Baseline:
- Defined the functional unit for LCA as: “Disinfection of one door handle with measured effectiveness,” comparing iST technology against a baseline of chemical disinfection in a hospital setting (San Sebastian Hospital).
- Developed a methodological framework to calculate a break-even point, determining the disinfection efficiency threshold at which the iST technology becomes environmentally preferable to chemical methods.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

1- Technical and scientific advances beyond current practice
SafeTouch delivers ultrafast, chemical-free thermal disinfection via sub-second joule-heating, outperforming passive surfaces reliant on heavy metal leaching, photocatalysis, or slow biocide release. It integrates flexible, high-power micro-heaters on chemically strengthened 100 µm glass, enabling 20 mm bendability, 0.75–1.25 W/cm² over 100 ms pulses, and >8,000 cycles stability. The system includes closed-loop temperature control and a touch-safe interlock, using resistance sensing (TCR 0.368 ± 0.026 Ω/°C) with ±1.5°C precision and capacitive proximity detection at 4–5 mm, triggering hardware cutoff in <10 µs. It is the first to demonstrate ISO 10993-5 cytocompatibility for such electrothermal microfilms, confirming non-cytotoxicity in L929 fibroblasts. It also applies the EU Safe and Sustainable by Design framework from M1, substituting two Level 0 substances (2-methoxypropyl acetate, tetramethylammonium hydroxide) and reducing seven Level 1 substances.

2- Potential impacts
If matured, the iST microfilm technology could deliver significant impacts. Clinically and in public health, it enables continuous, on-demand disinfection of high-touch surfaces in hospitals, care facilities, food processing, and public transport, with a projected 10–20% reduction in HAIs translating into thousands of lives saved and millions of hospital days freed annually in Europe. Environmentally, it replaces single-use wipes, chemical disinfectants, and water-intensive cleaning with a durable, reusable, consumable-free solution, aligned with SSbD-optimised low-impact manufacturing. Economically, it opens new market opportunities for European SMEs in the growing smart hygiene sector, with deployment pathways including licensing to door handle manufacturers, medical device firms, and building automation integrators. Scientifically, it contributes open-access knowledge on pathogen thermal inactivation on surfaces, flexible high-power microfabrication, and integration of touch-safe interlocks in smart surface technologies.