LIFT of polymer and polymer/nanocomposite materials
On‐Demand Laser Printing of Picoliter‐Sized, Highly Viscous, Adhesive Fluids
By using LIFT technique printing limitations in the Z range were overcome, resulting to printed droplets with high spatial resolution. Particularly, it was possible to print adhesives with viscosity values up to 1700 mPa s and Z down to 0.03. The effect of the laser fluence and the wettability of the substrate in improving the printing resolution is explained. It was found that for the cyanoacrylates, best resolution was achieved when using PDMS as a receiver substrate. By using LIFT printing of adhesives and subsequent localized deposition of chemical indicator powders, we demonstrated a novel fabrication concept for sensor microdevices that are able to detect small concentrations of various heavy metals in aqueous solutions.
Laser printing of polymers/CNT nanocomposites for amperometric sensors.
The incorporation of CNT into non-conductive polymer matrices can form conductive polymer composites, which are being used as new sensing materials for biosensors and chemical sensors. One of the most important challenges for the fabrication of these sensing devices is the deposition of the polymer/CNT composites onto the sensing elements. In particular, the fabrication of microsensors demands accurate deposition and/or pattering of polymer/CNT composite layers with submicron resolution. Since the common microelectronic techniques, such as photolithography, are difficult to implement on these complex materials, LIFT is an excellent alternative technique for direct and high spatial resolution dry and liquid printing of polymer/CNT composite patterns. LIFT is employed in a two-step process: the preparation of the target material and the selective deposition of a region of the target material through laser irradiation. The technique is applicable to a wide range of polymer/CNT composites, which may form uniform targets by spin coating or drop casting, regardless of the polymer and CNT concentration.
People Christos Boutopoulos, Postdoctoral Fellow, École Polytechnique de Montréal; Christos Pandis, Polymer Coatings Engineer at BIC, R&D Blade/Shavers; Marianneza Chatzipetrou, Postdoctoral Researcher, NTUA; Polykarpos Pissis, Professor, NTUA; Ioanna Zergioti, Professor, NTUA.
Laser printing of PANI.
We implement Laser Induced Forward Transfer (LIFT) of polyaniline films for microbiosensor applications. Polyaniline films are printed in the solid phase by Laser Induced Forward Transfer directly in between aluminum electrodes lying on a glass substrate. To apply solid-phase laser printing, aniline is in situ polymerized on quartz substrates. The electrical characteristics of printed polyaniline present ohmic behavior, allowing for the use of these substrates in electrochemical biosensing applications.
People Maria Kandyla, Senior Researcher, TPCI/NHRF; Christos Pandis, Polymer Coatings Engineer at BIC, R&D Blade/Shavers; Stavros Chatzandroulis, Senior Researcher, Dept.of Microelectronics, NCSR "Demokritos"; Ioanna Zergioti, Professor, NTUA.
Funding EU project, Marie Curie IRG, BIOLIFT (2008-2012)