Safety assessment of barrier materials in HI-ACCURACY

Safety assessment of barrier materials in HI-ACCURACY

Project Deliverable by BNN
Project: HI-ACCURACY (High-ACCuracy printed electronics down to µm size, for Organic Large Area Electronics (OLAE) Thin Film Transistor (TFT) and Display Applications – EU Grant Agreement No 862410)
Date of publication: October 2023
Area: Design for Technology Development (DfTD)
BNN team involvement: Susanne Resch, Clemens Wolf, Matiss Reinfelds

Barrier materials play a crucial role in protecting the active layer materials of printed electronics from moisture and oxygen. These barrier materials are remarkably thin, typically only a few tens of nanometres thick.

In this project report, the scientific research team of BNN presented a safety evaluation of barrier materials, focusing primarily on metal oxides, which are commonly used for this purpose.

Various coating technologies are available for the production of barrier materials, and within this report, we assessed two of them utilized in the HI-ACCURACY project: Atomic Layer Deposition (ALD) and Electrostatic Spray Assisted Vapor Deposition (ESAVD) along with its variations.
ALD is typically carried out in an enclosed environment, effectively minimizing worker exposure to any generated nanomaterials. However, this method has its drawbacks: it consumes a lot of energy and generates chemical waste (unused precursors). Additionally, it requires highly reactive precursors and can produce toxic by-products during the process.

On the other hand, ESAVD offers a promising alternative to ALD, characterized by lower energy consumption and the potential use of safer chemical precursors. To ensure worker safety when working with this coating technology, it is crucial to operate it in an enclosed environment. With appropriate ventilation in place, we anticipate that worker exposure to nanomaterials will remain low.

In summary, our safety evaluation underscores the importance of selecting the most suitable coating method for barrier materials, considering both worker safety and environmental sustainability. The choice between ALD and ESAVD should be made with a clear understanding of the associated risks and benefits, ultimately contributing to the safer and more sustainable development of printed electronics.

This report was supported by previous work performed within the scope of Hi-Response (“Innovative High Resolution Electro-Static printing of Multifunctional Materials”, H2020 NMP-PILOTS-Programme) and INSPIRED (“INdustrial Scale Production of Innovative nanomateRials for printEd Devices”, H2020 NMP-PILOTS-Programme). Further consultation with colleagues from the project Gov4Nano (“Implementation of Risk Governance: meeting the needs of nanotechnology”, H2020 NMBP-Programme) and the European NanoSafety Cluster (NSC), including its different Working Groups, enhanced interdisciplinary and international collaboration in the field of nanosafety and Safe-by-Design.