On-Demand Webinar:

Sensors & Switches

Date: October 19, 2011
Time: 12 PM EDT (9 AM PDT)
Duration: 0.75 hour


Scientific research carried out by ultrasonic and forest resources research groups (CSIC and CITA, respectively) demonstrated the possibility of using non-contact (air-coupled) ultrasonic spectroscopy (NCUS) to sense different properties of plant leaves in a fast and completely non-invasive way. How this rather novel technique works, and how it can be used for environmental applications are the main topics of this presentation.

The leaf properties that can be sensed are water content, water potential and variations in these parameters, the development stage of leaves and the influence of environmetal factors (light, watering, and presence of atmospheric pollutants) on plant development. This may have significant applications in watering management or monitoring of plant growth in agronomy. In addition, plants may act, in many different ways, a little like the miner's canary: an early warning system alerting us to important changes in our environment.

This new technique is described in detail as are the technical advances that have made it possible. What makes NCUS different from conventional ultrasonic techniques is also explained. Other potential applications of NCUS, also of interest in the field of environmental science, are outlined: detection of fouling in filtration membranes and aerogels, sensing of very soft tissues, etc.

Key Take-Aways

  • Learn about the novel technique of non-contact (air-coupled) ultrasonic spectroscopy
  • Understand the difference between conventional ultrasonic techniques and non-contact ultrasonic spectroscopy
  • Discover how to use this technique to determine, in a fast, non-invasive and continuous way, the variations of water potential, water content and other properties of plant leaves
  • Learn other applications of this technique


Tomás E. Gómez Alvarez-Arenas, Senior Researcher, Spanish Scientific Research Council

Tomás E. Gómez Alvarez-Arenas received the M.S. degree in Physics at Complutense University and the Ph.D. degree in Materials Science (Physics). He was a postdoctoral fellow at the Centre for Ultrasonic Engineering, University of Strathclyde (Glasgow, Scotland, U.K.) from 1995 to 1997, conducting research in the fields of air-coupled piezoelectric transducers and numerical modelling of ultrasonic wave propagation in random composites. He was elected to a fellowship at the Spanish National Research Council (CSIC) in 1998. In the Department of Ultrasonic Signals, Systems and Technologies he was appointed tenured scientist in 1999. From 2003 to 2007 he held the post of chief of this department. At present he is also involved in the starting up of a spin-off company, Drysonix, which will produce special ultrasonic sensors for novel applications in several industries.

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