Fernandez-Salmeron J.,TU Munich |
Rivadeneyra A.,TU Munich |
Rodriguez M.A.C.,ECsens. |
Rodriguez M.A.C.,University of Granada |
And 3 more authors.
IEEE Sensors Journal | Year: 2015
This paper describes printed resonant structures on a flexible substrate for humidity detection. The devices consist of a screen-printed spiral inductor working as radio frequency identification (RFID) antenna and two different inkjet-printed planar capacitive structures forming LC resonators. The sensitive material is directly the chosen substrate: a polyimide whose electrical permittivity is dependent on the moisture content. Therefore, no extra sensitive layer is required to functionalize these structures. In particular, two different approaches can be followed to use it. On one hand, the resonant structure can be used as a threshold tag including an RFID chip. The tags will be detected or not by an RFID reader depending on the humidity. On the other hand, these structures can be directly used as quantitative humidity sensors where the moisture content is associated with the resonant frequency of the structure. © 2015 IEEE.
Carvajal M.A.,ECsens. |
Ballesta-Claver J.,University of Granada |
Morales D.P.,ECsens. |
Palma A.J.,ECsens. |
And 2 more authors.
Sensors and Actuators, B: Chemical | Year: 2012
A portable reconfigurable instrument platform for electrochemiluminescence (ECL)-based disposable screen-printed electrodes is described. The reader unit consists of a potentiostat and a photodiode as a light-to-current converter integrated in the same instrument. For powerful and versatile analog conditioning, a very recent electronic solution has been included: a Field Programmable Analog Array (FPAA) capable of reconfiguring filter and gain stages in real time. To check the instrument's performance as a sensor platform, two luminophores (tris(2,2′bipyridyl)ruthenium(II) and luminol) and two representative correactants widely used, triethylamine and cholesterol, were selected. The calibration functions obtained show a linear dependence with dynamic ranges from 0.05 to 10.0 mg l -1 for triethylamine, and 2.0·10 -5-1.4·10 -4 M for cholesterol, with detection limits of 0.2 mg l -1 and 1.1·10 -5 M, respectively, and a sensor-to-sensor reproducibility (relative standard deviation, RSD) of around 3.2% and 3.3% respectively at the medium-range level. This instrument offers a new advance in the portability of electrochemiluminescent determinations. © 2012 Elsevier B.V. All rights reserved.