Fabrication Of Interdigitated Electrodes Research Articles

Piezoelectric Nanogenerators based on Lead Zirconate Titanate nanostructures: an insight into the effect of potential barrier and morphology on the output power generation

The high internal resistance of the perovskite materials used in Nanogenerators (NGs) lowers the power generation. It severely restricts their application for mechanical energy harvesting from the ambient source. In this work, we demonstrate a flexible Piezoelectric NG (PENG) with an improved device structure. Hydrothermally grown one-dimensional Lead Zirconate Titanate (Pb(ZrTi)O3) of different morphologies are used as the generating material. The morphology of the PZT nanostructures, engineered from nanoparticles to needle-shaped nanowires to increase the surface to volume ratio, provides effective mechanical contact with the electrode. The reduction of the internal resistance of the PENG has been achieved by two ways: (i) fabrication of interdigitated electrodes (IDE) to increase the interfacial polarization and (ii) lowering of Schottky barrier height (SBH) at the junction of the PZT nanostructure and the metal electrode by varying the electrode materials of different work functions. We find that lowering of the SBH at the interface contributes to an increased piezo voltage generation. The flexible nano needles-based PENG can deliver output voltage 9.5 V and power density 615 μW cm−2 on application low mechanical pressure (∼1 kPa) by tapping motion. The internal resistance of the device is ∼0.65 MΩ. It can charge a 35 μF super-capacitor up to 5 V within 20 s. This study provides a systematic pathway to solve the bottlenecks in the piezoelectric nanogenerators due to the high internal resistance.

3D Printed e-Tongue.

Nowadays, one of the biggest issues addressed to electronic sensor fabrication is the build-up of efficient electrodes as an alternative way to the expensive, complex and multistage processes required by traditional techniques. Printed electronics arises as an interesting alternative to fulfill this task due to the simplicity and speed to stamp electrodes on various surfaces. Within this context, the Fused Deposition Modeling 3D printing is an emerging, cost-effective and alternative technology to fabricate complex structures that potentiates several fields with more creative ideas and new materials for a rapid prototyping of devices. We show here the fabrication of interdigitated electrodes using a standard home-made CoreXY 3D printer using transparent and graphene-based PLA filaments. Macro 3D printed electrodes were easily assembled within 6 min with outstanding reproducibility. The electrodes were also functionalized with different nanostructured thin films via dip-coating Layer-by-Layer technique to develop a 3D printed e-tongue setup. As a proof of concept, the printed e-tongue was applied to soil analysis. A control soil sample was enriched with several macro-nutrients to the plants (N, P, K, S, Mg, and Ca) and the discrimination was done by electrical impedance spectroscopy of water solution of the soil samples. The data was analyzed by Principal Component Analysis and the 3D printed sensor distinguished clearly all enriched samples despite the complexity of the soil chemical composition. The 3D printed e-tongue successfully used in soil analysis encourages further investments in developing new sensory tools for precision agriculture and other fields exploiting the simplicity and flexibility offered by the 3D printing techniques.

Fabrication of interdigitated electrodes by inkjet printing technology for apllication in ammonia sensing

In this paper interdigitated electrodes for gas sensors were fabricated by inkjet printing technology. Silver electrodes were inkjet printed on Si/SiO2 substrates instead of traditional photolithography method. The inkjet printing parameters to obtain desired dimensions, thickness of the electrodes and distance between the interdigitated electrodes were optimized in this study. The fabricated interdigitated silver electrodes were tested for application in ammonia gas sensors. Conductive polyaniline (PANI) layer was coated on the silver interdigitated electrodes by drop-coating. Ammonia detection of the PANI-coated chips was characterized with a gas measurement system in which humidity and ammonia concentrations were well-controlled. The electrical conductivity of the PANI films coated on the electrodes was measured when the PANI films were exposed to nitrogen and ammonia. The conductivity of the PANI films decreased significantly due to the deprotonation process of PANI upon ammonia expodure. The recovery time was about 15 min by heating up the polymer chip at 60 °C. The results showed that the silver electrodes fabricated by inkjet printing technique could be used as a sensor platform for ammonia detection.

Fabrication of Aluminum Interdigitated Electrode for Biosensor Application Using Conventional Lithography

A simple technique for the fabrication of interdigitated electrode (IDEs) using conventional lithography was presented. A top-down simple lithography approach was used to fabricate a set of Interdigitated electrodes were patterned with aluminum metal. Silicon dioxide serves to isolate the electrode from the substrate. A chrome mask was proposed to complete this work. In this work, the proposed method was experimentally demonstrated by fabricating the IDEs structure 4-5μm, approximately. The dimensions of structure were determined by using scanning electron microscopy (SEM). It is a simple, easy-to-use and cost effective method and does not require complicated micro-lithography process for fabricating desired microelectrode in reproducible approach.

Fabrication of Interdigitated Electrodes using Molecular Beam Epitaxy and Optical Lithography

ABSTRACTThis study reports the fabrication of interdigitated electrodes using molecular beam epitaxy and photolithography techniques. Sandwich-based 10 nm silver and 50 nm gold films were deposited on glass substrates using magnetron sputtering and molecular beam epitaxy deposition. The thickness and roughness were determined by use of a suitable mathematical model and ellipsometric measurements. The gold film (111) orientation was determined by X-ray diffraction. Optical microscopy measurements were made for the lateral resolution determination of the fabricated electrodes and the quality was similar to that of the photomask. Atomic force microscopy measurements offered information regarding the topography of the sample and the possible application of the fabricated system for molecular detection.

Development of an electronic nose sensing platform for undergraduate education in nanotechnology

The teaching of the different aspects of a sensor system, with a focus on the involved nanotechnology, is a challenging, yet important task. We present the development of an electronic nose system that utilizes a nanoscale amperometric sensing mechanism for gas mixtures. The fabrication of the system makes use of a basic microfabrication facility, as well as an undergraduate chemistry laboratory for material synthesis and preparation. The sensing device consists of an array of cross-reactive sensors composed of metal-oxide semiconducting nanoparticles. Each sensor in the array produces a unique response in the presence of a target gas, allowing the sensor to determine the identity and concentration of multiple gases in a mixture. The educational aspects include microheater simulation and fabrication, design and fabrication of interdigitated electrodes, development of interfacing circuitry and software, development and calibration of a sensory array, sol–gel processing of nanoparticle films and their characterization, and details of the fundamental chemical sensing mechanism.

Nanostructuring of polymers and fabrication of interdigitated electrodes by hot embossing lithography

We investigated the possibilities of Hot Embossing Lithography (HEL) as a novel technique for the replication of nanostructures. A replication fidelity in polymers of less than 10 nm was achieved using anisotropically etched Si-substrates as masters. We demonstrated that nanoimprinting combined with the lift-off technique can be used to fabricate arrays of interdigitated metal electrodes. The electrodes have a length of 100 μm and a spacing between the electrodes of 200 nm, and are defect-free over an area of 10 μm × 100 μm.