Dual element transducer

Dual element transducer is an extended example of multiple probe technique in which one element acts as emitter and the other as receiver. These transducers are designed for measuring very thin materials or when detecting near surface discontinuities. Using this concept, it is possible to focus the ultrasonic beam. One of the major uses of focused probes is defect sizing by means of diffraction techniques. 

The hydrophobias are a case where protein nanofibers can play a dual role in creating a biosensor. They can aid in the immobilization of bioactive components within a biosensor and also add further functionality to the transducing element of a biosensor device. Hydrophobins are self-assembling [3-sheet structures observed on the hyphae of filamentous fungi. They are surface active and aid the adhesion of hyphae to hydrophobic surfaces (Corvis et al., 2005). These properties can be used to create hydrophobia layers on glass electrodes. These layers can then facilitate the adsorption of two model enzymes glucose oxidase (GOX) and hydrogen peroxidase (HRP) to the electrode surface. The hydrophobin layer also enhances the electrochemical properties of the electrodes. 

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