Hydrogen sensing via anomalous optical absorption of palladium-based metamaterials

A. Hierro-Rodriguez (Lead / Corresponding author), I. T. Leite, P. Rocha-Rodrigues, P. Fernandes, J. P. Araujo, P. A S Jorge, J. L. Santos, J. M. Teixeira, A. Guerreiro

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


A palladium (Pd)-based optical metamaterial has been designed, fabricated and characterized for its application in hydrogen sensing. The metamaterial can replace Pd thin films in optical transmission schemes for sensing with performances far superior to those of conventional sensors. This artificial material consists of a palladium-alumina metamaterial fabricated using inexpensive and industrial-friendly bottom-up techniques. During the exposure to hydrogen, the system exhibits anomalous optical absorption when compared to the well-known response of Pd thin films, this phenomenon being the key factor for the sensor sensitivity. The exposure to hydrogen produces a large variation in the light transmission through the metamembrane (more than 30% with 4% in volume hydrogen-nitrogen gas mixture at room temperature and atmospheric pressure), thus avoiding the need for sophisticated optical detection systems. An optical homogenization model is proposed to explain the metamaterial response. These results contribute to the development of reliable and low-cost hydrogen sensors with potential applications in the hydrogen economy and industrial processes to name a few, and also open the door to optically study the hydrogen diffusion processes in Pd nanostructures.

Original languageEnglish
Article number185501
Issue number18
Early online date22 Mar 2016
Publication statusPublished - 6 May 2016


  • hydrogen sensing
  • nanoporous aluminum oxide templates
  • optical metamaterial

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Electrical and Electronic Engineering
  • Mechanical Engineering
  • Mechanics of Materials
  • Materials Science(all)


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