Search results for "Inkjet printing"

Interfacial fragmentation and electrical characterization of inkjet printed dil droplets

2019

This work presents a novel mechanism for the spontaneous fragmentation of picoliter-scale oil droplets at the interface with an immiscible water phase, and the electrical characterization of the resulting immersed “daughter” droplets by an electrical impedance chip (see Figure). [1] In particular, picoliter-scale fluorinated oil droplets are produced by inkjet printing at velocity higher than 5 m/s. Upon impact on the surfactant laden water phase at moderately high Weber number , i.e. around 10, the oil droplet is subjected to spreading and capillary instabilities at the water/air interface. These ultimately lead to its rupture in smaller sized droplets, according to the reported models for…

Printing Biology for Advanced Synthetic Biosystem

2019

Printing technologies represent a powerful tool for the direct micro- and nano- fabrication of biomolecular structures at the interface between life and materials sciences (Arrabito et al., 2012). Their continuous development over the last years has permitted the onset of man-made biosystems with customizable dimensions (from the micron-scale down to the nanometer scale), composition (organic molecules, DNA, proteins, phospholipids), and relevant functions (molecular interactions, drug screening, cellular biointerfaces, cell-like compartments). In this work, we show the possibility to leverage the fabrication of a wide class of solid-supported or liquid-liquid based synthetic compartments b…

Micro and Nano patterns for Biosensing: from enzymatic assays to single cells interaction arrays

2012

In this thesis work, solution dispensing techniques have been employed for the realization of complex biological arrays. Inkjet printing techniques were employed for the generation of drug screening platforms. This approach was initially proved with a model enzyme system like Glucose Oxidase substrate covalently linked to a functionalized silicon oxide support. On this support an enzymatic substrate (D-glucose)/inhibitor (D-glucal) couple was accurately dispensed. A simple optical detection method was used to prove the screening capability of the microarray with the possibility to assay with high reproducibility at the single spot level. Afterwards, this methodology has been extended to CYP…

Metodologie da stampa a getto d'inchiostro per la fabbricazione di substrati SERS

2019

Uno degli argomenti di maggiore interesse della Surface-enhanced Raman spectroscopy (SERS) è il controllo del posizionamento su superficie degli “hot spots” – le zone interstiziali fra aggregati di particelle metalliche che producono un aumento locale del segnale Raman. I substrati SERS consistono tipicamente in una matrice di hot-spots ad alta densità sui quali volumi macroscopici (>1 µL) di molecole di analita sono disperse. Questo approccio porta ad una alta invasività ed una distribuzione non uniforme dell’analita a causa dei flussi capillari. In questo lavoro, viene sviluppata una nuova piattaforma SERS realizzata da stampa a getto d’inchiostro2 in cui una miscela di un analita SERS…

High-throughput screening at the picoliter scale by combining Dip Pen Lithography with Inkjet printing

Drug screening is a complex, expensive and time consuming field consisting of diseasebased target identification in conjunction with high-throughput screening of chemical and natural product libraries. Conventional drug screening technology is usually time and reagent consuming (micro-, nanoliter scale) and is based on complex liquid handling robotics. In this work, we show a low-cost and miniaturized drug screening methodology based on direct bio-printing methodologies like Inkjet Printing and Dip Pen Lithography. We show the possibility to precisely deliver femtoliter scale droplets of protein targets by Dip Pen Lithography by finely tuning deposition parameters. This allows obtaining mic…

Oil-in-Water fL Droplets by Interfacial Spontaneous Fragmentation and Their Electrical Characterization

2019

Inkjet printing is here employed for the first time as a method to produce femtoliter-scale oil droplets dispersed in water. In particular, picoliter-scale fluorinated oil (FC40) droplets are printed in the presence of perfluoro-1-octanol surfactant at a velocity higher than 5 m/s. Femtoliter-scale oil droplets in water are spontaneously formed through a fragmentation process at the water/air interface using minute amounts of nonionic surfactant (down to 0.003% v/v of Tween 80). This fragmentation occurs by a Plateau-Rayleigh mechanism at a moderately high Weber number (10(1)). A microfluidic chip with integrated microelectrodes allows droplets characterization in terms of number and diamet…

Printing ZnO Inks: From Principles to Devices

2020

Solution-based printing approaches permit digital designs to be converted into physical objects by depositing materials in a layer-by-layer additive fashion from microscale to nanoscale resolution. The extraordinary adaptability of this technology to different inks and substrates has received substantial interest in the recent literature. In such a context, this review specifically focuses on the realization of inks for the deposition of ZnO, a well-known wide bandgap semiconductor inorganic material showing an impressive number of applications in electronic, optoelectronic, and piezoelectric devices. Herein, we present an updated review of the latest advancements on the ink formulations an…

Inkjet Printable ZnO/PEDOT:PSS Heterojunction for Thin Flexible Semi-Transparent Optoelectronic Sensors

2020

International audience; Flexible sensors play an increasing role in printed electronics and are of interest for optoelectronic applications in flexible robotics and industrial automation. Thus, we have investigated the hybrid inorganic-organic junction between ZnO and PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate). A thin ITO (indium tin oxide) layer on PET (polyethylene terephthalate) foils was used as substrate electrode. ZnO was deposited from a nanoparticle (NP) suspension by electrophoretic deposition. For comparison, we have used three different methods for the deposition of PEDOT:PSS, namely (i) drop casting, (ii) dip-coating, (iii) inkjet printing. For the result…

Autonomous molecularly crowded confinement in inkjet printed femtoliter-scale aqueous compartments

2019

Natural evolution has chosen the localization of biomolecular processes into crowded sub-cellular femtoliter (fL) scale compartments for organizing complex biological processes. [1] Many synthetic biology platforms with life-like activities have been able to mimic these systems under different compartment sizes regimes. [2] However, the fabrication of crowded compartments down to sub-cellular scales is challenging, mainly because of high surface-volume ratio of these systems, finally compromising the stability of the encapsulated biomolecules. In this regard, we here bridge this gap by showing the possibility to produce femtoliter-scale aqueous droplets using a novel inkjet printing approac…

High-throughput drug screening by Printing Biology

2015

Printing biology is our way to define a novel field employing material printing techniques generally used in plastic electronics to solve important issues of biology by miniaturized and high-throughput platforms. In this field, we already showed the possibility to use Dip Pen Lithography to fabricate single-cell biochips [1]. Also,we employed non-contact patterning methods such as inkjet printing methods to fabricate microarrays for drug screening at solid-liquid interfaces [2] or in picoliter-scale liquid droplets [3] so enabling high-throughput screening of chemical libraries onto disease-based targets. In this regard, printing methods would greatly reduce times and costs of standard drug…