Laurenti M.,Italian Institute of Technology |
Laurenti M.,Polytechnic University of Turin |
Stassi S.,Polytechnic University of Turin |
Lorenzoni M.,Italian Institute of Technology |
And 8 more authors.
Nanotechnology | Year: 2015
Local piezoresponse and piezoelectric output voltage were evaluated on ZnO thin films deposited by radio-frequency magnetron sputtering on hard Si/Ti/Au and flexible Cu-coated polyimide substrates. Three different thicknesses of ZnO films were studied (285 nm, 710 nm, and 1380 nm), focusing on characteristics like crystallinity, grain size, surface roughness, and morphology. Independent of the nature of the metal layer and the substrate, our results show that thicker films presented a higher level of crystallinity and a preferential orientation along the c-axis direction, as well as a lower density of grain boundaries and larger crystal sizes. The improvement of the crystalline structure of the material directly enhances its piezoelectric properties, as confirmed by the local characterizations performed by piezoresponse force microscopy and by the evaluation of the output voltage generation under the application of a periodical mechanical deformation on the whole film. In particular, the highest value of the d33 coefficient obtained (8 pm V-1) and the highest generated output voltage (0.746 V) belong to the thickest films on hard and flexible substrates, respectively. These results envision the use of ZnO thin films - particularly on flexible substrates - as conformable, reliable, and efficient active materials for use in nanosensing, actuation, and piezoelectric nanogenerators. © 2015 IOP Publishing Ltd.
Tosolini G.,Barcelona Microelectronics Institute |
Scarponi F.,University of Tuscia |
Cannistraro S.,University of Tuscia |
Bausells J.,Barcelona Microelectronics Institute
Applied Physics Letters | Year: 2013
Highly sensitive sensors are one of the enabling technologies for the biomarker detection in early stage diagnosis of pathologies. We have developed a self-sensing nanomechanical force probe able for detecting the unbinding of single couples of biomolecular partners in nearly physiological conditions. The embedding of a piezoresistive transducer into a nanomechanical cantilever enabled high force measurement capability with sub 10-pN resolution. Here, we present the design, microfabrication, optimization, and complete characterization of the sensor. The exceptional electromechanical performance obtained allowed us to detect biorecognition specific events underlying the biotin-avidin complex formation, by integrating the sensor in a commercial atomic force microscope. © 2013 AIP Publishing LLC.
Villanueva L.G.,Ecole Polytechnique Federale de Lausanne |
Vazquez-Mena O.,Ecole Polytechnique Federale de Lausanne |
Martin-Olmos C.,Ecole Polytechnique Federale de Lausanne |
Savu V.,Ecole Polytechnique Federale de Lausanne |
And 7 more authors.
Journal of Micromechanics and Microengineering | Year: 2012
The standard lithographic techniques to fabricate electronic components involve the use of polymers, baking steps and chemicals. This typically restricts their application to flat substrates made up of standard materials. Stencil lithography has been proposed as a stable alternative to the standard lithographic techniques. In this paper, we demonstrate the completely resistless all-through-stencil fabrication of electronic components, by performing all essential fabrication steps - implantation, etching and metallization - using stencil lithography. This is performed on a planar substrate as well as on pre-patterned 3D substrates, thus showing the potential of this technique for applications in the field of accelerometers, pressure, gas and radiation sensors. © 2012 IOP Publishing Ltd.
Birhane Y.,Barcelona Microelectronics Institute |
Otero J.,Institute Of Bioenginyeria Of Catalonia Ibec |
Perez-Murano F.,Barcelona Microelectronics Institute |
Fumagalli L.,Institute Of Bioenginyeria Of Catalonia Ibec |
And 4 more authors.
Microelectronic Engineering | Year: 2014
We report a novel fabrication process for the batch fabrication of insulated conductive scanning probe microscopy (SPM) probes for electrical and topographic characterization of soft samples in liquid media at the nanoscale. The whole SPM probe structure is insulated with a dielectric material except at the very tip end and at the contact pad area to minimize the leakage current in liquid. Additionally, the geometry of the conducting layer in the probe cantilever and substrate is engineered to reduce the parasitic capacitance coupling with the sample. The electrical characterization of the probes has shown that parasitic capacitances are significantly reduced as compared to fully metallized cantilevers. © 2014 Elsevier B.V. All rights reserved.
Bausells J.,Barcelona Microelectronics Institute |
Tosolini G.,Barcelona Microelectronics Institute |
Birhane Y.M.,Barcelona Microelectronics Institute |
Perez-Murano F.,Barcelona Microelectronics Institute
8th Annual IEEE International Conference on Nano/Micro Engineered and Molecular Systems, IEEE NEMS 2013 | Year: 2013
We have developed self-sensing piezoresistive microcantilevers optimized for the measurement of (biomolecular) forces. Typical dimensions are 250 μm in length, 8-20 μm in width and 450 nm in thickness, with spring constants of about 1 mN/m. The devices have been electromechanically tested on wafer and show good force resolutions in air between 35 and 130 pN depending on the cantilever dimensions. We have also tested the electromechanical behavior of the cantilevers in liquid environment and we show that both the force sensitivity and the noise characteristics of the devices are not noticeably degraded as compared with their response in air. This opens the way to the use of the cantilevers in single molecule force spectroscopy of biomolecules. © 2013 IEEE.