Frequency-selective surfaces by nanosecond laser-ablation
High insulation windows generally have the disadvantage that they do not let phone waves penetrate. In trains with such windows, this made it necessary for train companies to install expensive repeater technology that needs regular updating.
To address this problem, the LESO-PB nano group has a way to laser engrave high insulation films, which allows phone waves to penetrate but hardly impedes insulation.
This technology was recently installed in 32 trains of the Bernese regional train company BSL and has met considerable interest from companies around the globe. While the technology is especially useful in trains, it will also find application in buildings.
Main publications
Luc Burnier ; Matteo Lanini ; Olivia Bouvard ; Damiano Scanferla ; Abiraam Varathan ; Carine Genoud ; Arnaud Marguerit ; Bernard Cuttat ; Noémie Dury ; Reiner Witte ; Andrea Salvadè ; A. Schüler, Energy saving glazing with a wide band-pass FSS allowing mobile communication: Upscaling and characterization, in IET Microwaves, Antennas & Propagation, DOI: 10.1049/iet-map.2016.0685
Structured transparent low emissivity coatings with high microwave transmission, in Applied Physics a Materials Science and Processing, vol. 123, num. 66, 2017. DOI: 10.1007/s00339-016-0701-8
Awards
RailTech 2019 Innovation Award, Utrecht, to Andreas Schüler, Olivia Bouvard, Luc Burnier, Jérémy Fleury, for Energy efficient windows that transmit telephone signals.
Watt d’Or 2019 awarded by the Swiss Federal Office of Energy, Category “Energy-efficient mobility” – Retrofit of 36 NINA suburban trains with LESO-PB’s novel technology of microwave-transparent insulating glazing, in collaboration with BLS and the University of Basel – P.Oelhafen, C. Isenschmid, A. Schüler et al.
In the media – New train windows allow mobile phone waves through while keeping excellent energy efficiency:
RTS – CQFD: Réception mobile dans les trains: une solution de l’EPFL
RTS : Des vitres de trains traitées au laser pour faciliter les coups de téléphone
20 minutes : Nouveau vitrage pour mieux téléphoner en train
Tribune de Genève : Nouveau vitrage pour mieux téléphoner en train
24heures : Nouveau vitrage pour mieux téléphoner en train
24heures: Des vitres innovantes conjugent isolation et téléphonie mobile
Tages Anzeiger : Besserer Handyempfang im Zug dank neuer Fensterscheiben
Berner Zeitung : Besserer Handyempfang im Zug dank neuer Fensterscheiben
St.Galler Tagblatt : Neue Zugfenster lassen Mobilfunk durch
Neue Luzerner Zeitung : Neues Glas für Zugfenster lässt Mobilfunk durch
EPFL Flash: Train windows that combine mobile reception and thermal insulation