PhD Student at École de technologie supérieure studying Carbon Nanotube MEMS.
Taking the idea of printed electronics to a whole new level
From Printing paper to Printing electronic circuits Consider printing an electronic circuit at home using a multi functional printer or printing a light bulb to replace a broken one. It is getting one step closer to reality using Aerosol Jet Printing What is Aerosol Jet Printing (AJP)? AJP is a Computer Aided Design (CAD) driven vector based printing method that uses a sheath of inert gas to tightly focus a beam of aerosol onto a substrate. The Aerosol Jet process cost effectively prints high resolution electronic circuits and components on 2D and 3D surfaces from a wide range of materials including conductive nano-particle metal inks, dielectric pastes, semiconductor and other functional materials. Potential Applications enabled by AJP The technology behind Aerosol Jet can print electronic and biological components onto 2D and 3D surfaces. By tightly integrating electronic circuitry with physical packaging, Aerosol Jet is fueling growth in new consumer and military applications where increased functionality in smaller spaces is a key driving factor. Leading research institutes have successfully fabricated all elements of a Thin Film Transistor (TFT) using Aerosol Jet printing technology without involving any photolithography patterning or surface pretreatment steps. The unique multi-material deposition capability of Aerosol Jet technology enabled four distinct materials to be printed into four separate layers to print CNT-TFTs
Abstract: The coffee ring effect is reduced effectively and a hydrogen sensor with platinum-decorated single-walled carbon nanotubes (SWCNTs) is prepared by aerosol jet printing (AJP) technology. The stable aqueous solution of platinum functional SWCNTs is prepared by a series of chemical and physical processes and the electrode array is formed by micro-fabrication technology. The AJP process is also researched in detail including the number of printing passes and the printing distance between electrodes. Then, the functional SWCNT aqueous solution is printed on the electrode array and the response of this sensor to the hydrogen is measured carefully. The results show that a functional SWCNT sensor has excellent sensing properties toward hydrogen.
Pub.: 21 Nov '12, Pinned: 30 Apr '17
Abstract: Active layers of polymer solar cells were prepared by aerosol jet printing of organic inks. Various solvents and additives with high boiling points were screened for the preparation of high-quality polymer films. The effects on device performance of treating the films by thermal and solvent vapor annealing were also investigated. The components of the solvent were important for controlling the drying rate of the liquid films, reducing the number of particle-like protrusions on the film surface, and realizing high molecular ordering in the polymer phases. The optimized solar cell device with poly(3-hexylthiophene) and a C(60) derivative showed a high fill factor of 67% and power conversion efficiency of 2.53% without thermal annealing. The combination of poly[N-9-heptadecanyl-2,7-carbazole-alt-3,6-bis(thiophen-5-yl)-2,5-diethylhexyl-2,5-dihydropyrrolo-[3,4-]pyrrole-1,4-dione] and a C(70) derivative led to power conversion efficiency of 3.92 and 3.14% for device areas of 0.03 and 1 cm(2), respectively.
Pub.: 16 Sep '11, Pinned: 30 Apr '17
Abstract: Carbon and post-carbon nanomaterials present desirable electrical, optical, chemical, and mechanical attributes for printed electronics, offering low-cost, large-area functionality on flexible substrates. In this Perspective, recent developments in carbon nanomaterial inks are highlighted. Monodisperse semiconducting single-walled carbon nanotubes compatible with inkjet and aerosol jet printing are ideal channels for thin-film transistors, while inkjet, gravure, and screen-printable graphene-based inks are better-suited for electrodes and interconnects. Despite the high performance achieved in prototype devices, additional effort is required to address materials integration issues encountered in more complex systems. In this regard, post-carbon nanomaterial inks (e.g., electrically insulating boron nitride and optically active transition-metal dichalcogenides) present promising opportunities. Finally, emerging work to extend these nanomaterial inks to three-dimensional printing provides a path toward nonplanar devices. Overall, the superlative properties of these materials, coupled with versatile assembly by printing techniques, offer a powerful platform for next-generation printed electronics.
Pub.: 12 Aug '15, Pinned: 30 Apr '17
Abstract: Two innovative research studies are reported in this paper. One is the sorting of semiconducting carbon nanotubes and ink formulation by a novel semiconductor copolymer and second is the development of CMOS inverters using not the p-type and n-type transistors but a printed p-type transistor and a printed ambipolar transistor. A new semiconducting copolymer (named P-DPPb5T) was designed and synthesized with a special nonlinear structure and more condensed conjugation surfaces, which can separate large diameter semiconducting single-walled carbon nanotubes (sc-SWCNTs) from arc discharge SWCNTs according to their chiralities with high selectivity. With the sorted sc-SWCNTs ink, thin film transistors (TFTs) have been fabricated by aerosol jet printing. The TFTs displayed good uniformity, low operating voltage (±2 V) and subthreshold swing (SS) (122–161 mV dec−1), high effective mobility (up to 17.6–37.7 cm2 V−1 s−1) and high on/off ratio (104–107). With the printed TFTs, a CMOS inverter was constructed, which is based on the p-type TFT and ambipolar TFT instead of the conventional p-type and n-type TFTs. Compared with other recently reported inverters fabricated by printing, the printed CMOS inverters demonstrated a better noise margin (74% 1/2 Vdd) and was hysteresis free. The inverter has a voltage gain of up to 16 at an applied voltage of only 1 V and low static power consumption.
Pub.: 26 Jan '16, Pinned: 30 Apr '17
Abstract: Printed Electronics has emerged as an important fabrication technique that overcomes several shortcomings of conventional lithography and provides custom rapid prototyping for various sensor applications. In this work, silver microelectrode arrays (MEA) with three different electrode spacing were fabricated using 3-D printing by the aerosol jet technology. The microelectrodes were printed at a length scale of about 15 μm, with the space between the electrodes accurately controlled to about 2 times (30 μm, MEA30), 6.6 times (100 μm, MEA100) and 12 times (180 μm, MEA180) the trace width, respectively. Hydrogen peroxide and glucose were chosen as model analytes to demonstrate the performance of the MEA for sensor applications. The electrodes are shown to reduce hydrogen peroxide with a reduction current proportional to the concentration of hydrogen peroxide for certain concentration ranges. Further, the sensitivity of the current for the three electrode configurations was shown to decrease with an increase in the microelectrode spacing (sensitivity of MEA30: MEA100: MEA180 was in the ratio of 3.7: 2.8: 1), demonstrating optimal MEA geometry for such applications. The noise of the different electrode configurations is also characterized and shows a dramatic reduction from MEA30 to MEA100 and MEA180 electrodes. Further, it is shown that the response current is proportional to MEA100 and MEA180 electrode areas, but not for the area of MEA30 electrode (the current density of MEA30 : MEA100 : MEA180 is 0.25 : 1 : 1), indicating that the MEA30 electrodes suffer from diffusion overlap from neighboring electrodes. The work thus establishes the lower limit of microelectrode spacing for our geometry. The lowest detection limit of the MEAs was calculated (with S/N = 3) to be 0.45 μM. Glucose oxidase was immobilized on MEA100 microelectrodes to demonstrate a glucose biosensor application. The sensitivity of glucose biosensor was 1.73 μAmM(-1) and the calculated value of detection limit (S/N = 3) was 1.7 μM. The electrochemical response characteristics of the MEAs were in agreement with the predictions of existing models. The current work opens up the possibility of additive manufacturing as a fabrication technique for low cost custom-shaped MEA structures that can be used as electrochemical platforms for a wide range of sensor applications.
Pub.: 29 Mar '16, Pinned: 30 Apr '17
Abstract: Transparent, conductive electrodes are important in many applications such as touch screens, displays and solar cells. Transparent energy storage systems will require materials that can simultaneously act as current collectors and active storage media. This is challenging as it means improving the energy storage capability of conducting materials while retaining transparency. Here, we have used aerosol-jet spraying strategy to prepare transparent supercapacitor electrodes from ruthenium oxide/poly(3,4-ethylenedioxythiophene): poly(styrene-4-sulfonate), (RuO2/PEDOT: PSS) hybrid thin films. These films combine excellent transparency with reasonably high conductivity (DC conductivity =279 S/cm) and excellent volumetric capacitance (CV =190 F/cm3). We demonstrate electrodes with historical high transparency of 93% which display an areal capacitance of C/AC/A=1.2 mF/cm2, significantly higher than the rest reported electrodes with comparable transparency. We have assembled flexible, transparent, solid-state symmetric devices which exhibit T =80% and C/AC/A=0.84 mF/cm2 and are stable over 10,000 charge/discharge cycles. Asymmetric solid-state device with RuO2/PEDOT: PSS and PEDOT: PSS thin films as positive and negative electrodes, respectively, display an areal capacitances of 1.06 mF/cm2, a maximum power density (P/A)(P/A) of 147 μW/cm2 and an energy density (E/A)(E/A) of 0.053 μWh/cm2. Furthermore, large area transparent solid-state supercapacitor device has been built. We believe the solution-processed transparent films could be easily scaled-up to meet the industrial demands.
Pub.: 27 Aug '16, Pinned: 30 Apr '17
Abstract: Inkjet and aerosol jet printing have recently emerged as promising fabrication techniques for a broad range of devices for electrochemical energy conversion and storage – batteries, fuel cells, and supercapacitors. If fully realized, these printing techniques may enable device performance advantages accruing from precise micron scale patterning, thin layer deposition, and materials grading. Printing may also allow scalable, low materials waste manufacturing, and conformal integration of power elements into structural elements. This article reviews the fundamental capabilities of inkjet and aerosol jet printing relevant to electrochemical devices, surveys current literature, and presents future challenges which must be tackled to achieve high performance, printed electrochemical energy storage, and conversion devices.
Pub.: 31 Mar '17, Pinned: 30 Apr '17
Abstract: Nanomaterials offer an attractive solution to the challenges faced for low-cost printed electronics, with applications ranging from additively manufactured sensors to wearables. This study reports hysteresis-free carbon nanotube thin-film transistor (CNT-TFTs) fabricated entirely using an aerosol jet printing technique; this includes the printing of all layers: semiconducting CNTs, metallic electrodes, and insulating gate dielectrics. It is shown that, under appropriate printing conditions, the gate dielectric ink can be reliably printed and yield negligible hysteresis and low threshold voltage in CNT-TFTs. Flexible CNT-TFTs on Kapton film demonstrate minimal variations in performance for over 1000 cycles of aggressive bending tests. New insights are also gained concerning the role of charge trapping in Si substrate-supported devices, where exposure to high substrate fields results in irreversible degradation. This work is a critical step forward as it enables a completely additive, maskless method to fully print CNT-TFTs of direct relevance for the burgeoning areas of flexible/foldable, wearable, and biointegrated electronics.
Pub.: 10 Apr '17, Pinned: 30 Apr '17