Abstracts - Dipartimento di Elettronica Applicata

Meta 2010 & FEM 2010 – Rome, 13-15 December 2010
Pillar Type PDMS Nanocomposite Optical
Antenna for Liquid Detection Systems
Alessandro Massaro (1) , Fabrizio Spano (1) , Roberto Cingolani (2) , and
Athanassia Athanassiou (1),(3)
(1) Italian Institute of Technology IIT, Center of Biomolecular
Nanotechnologies
Arnesano (Le), Italy – E-mail: alessandro.massaro@iit.it
(2) Italian Institute of Technology IIT- Genova, Italy.
(3) National Nanotechnology Laboratory, Institute of Nanoscience of CNR of
Lecce – Italy
In this work we propose a new pillar sensor device suitable for detection of
liquid’s permittivity. Due to the ability to generate gold nanoparticles starting
from gold precursors by chemical reduction [1], polydimethylsiloxane
(PDMS) polymer is used. A pillar type layout is chosen in order to collect and
radiate the signal in an optical fiber probe. The radiated signal is enhanced by
the light scattering of the gold micro/nano particles and allows to perform an
high detection sensitivity during the deposition of an ethanol droplet on the
sensor: as shown in Fig. 1 (a) a reduction of the transmitted light intensity is
observed when the ethanol is detected. The detection corresponds to a
variation of the dielectric contrast dn due to the presence of ethanol. In Fig. 1
(b) is reported the experimental setup used for the measurements. The sensor
is also able to measure the evaporation effect of the ethanol droplet.
Optical radiated intensity [a.u.]
2200
2000
1800
1600
1400
1200
1000
800
600
Broad
lamp
source
Multimode
optical fiber
400
800 900 1000 1100 1200 1300 1400
�[nm]
OMA
Multimode
(a) optical fiber
(b)
PDMS-Au pillar
PDMS-Au pillar+ ethanol
dn
57
Optical fiber
probe
Optical fiber
source
Pillar type
sensor
Figure 1 – a) PDMS-Au pillar type sensor and detection of ethanol as reduction of the optical
transmitted intensity. Inset below: image of the fabricated PDMS-Au prototype with the
height of a single pillar of 1.5 mm, the diameter of 1 mm and the side of the square layout of
2.5 mm. Inset above: schematic diagram of the used experimental setup. b) Experimental
setup.
References
[1] Q. Zhang, J. J. Xu, Y. Liu, and H. Y. Cuen, “In-situ synthesis of poly(dimethylsiloxane)-
gold nanoparticles composite filmsand its application in microfluidic system,” Lab on
chip, 8, 352-357, 2008.