This paper presents the results of morphological study on nanosized nickel zinc ferrite (NZF) thick film using linseed oil as organic vehicle and nanosized NZF powder. First, NZF nanopowder is mixed with organic vehicle which consists of linseed oil, m-xylene and α-terpineol. Paste samples were screen printed onto alumina as substrate, dried and fired at different temperatures of 100°C, 200°C, and 300°C, respectively. Microscopic images of the samples and elemental analysis were observed to determine good dispersion of the active powder with the organic vehicle. Based on the results, the nanoparticles were uniformly dispersed, and images of thick films fired at 200°C and 300°C have shown clearly visible particles, indicating that at these temperatures, the organic vehicle has started to evaporate on the surface, revealing nanoparticles of the active powders. The elemental analysis confirmed this idea, of which carbon element of the organic vehicle gradually decreased with increasing temperature.

In this paper, nickel zinc ferrite (NZF) nanopowder was mixed with organic vehicle which consists of linseed oil, m-xylene and α-terpineol. Then the mixture was sonicated for 1 hour at 40°C in order to obtain homogenous paste, followed by printing it onto FR4 substrate using the screen printing technique to form the NZF thick film layer before dried at 100°C and later fired at 200°C. A basic square shape patch antenna by using silver paste was printed onto the NZF thick film layer and was compared with another patch antenna which was been printed without the NZF layer. The results showed that the antenna with NZF thick film layer has return loss of -10.97dB, resonant frequency 6.42GHz, bandwidth 3.9 and Q factor of 1.646, which is better compared to the antenna without the layer by 32.81%, 3.22%, 86.60% and 44.69% respectively.

Research on microstrip patch antenna (MPA) has been growing in the past few decades due to its planar profile and easy fabrication. Its simplicity of structure, which includes a conductive patch, a dielectric substrate, a ground plane, and a microstrip feeder, is making it more popular for integration in devices which are more focused on miniaturization and flexibility. There are, however, a few disadvantages of MPA, such as narrow bandwidth, low power, and limited inexpensive material selection if a current printed circuit board etching fabrication technique is used. Ferrite substrates are known to be able to help overcome this issue, but the properties of bulk ferrites are difficult to control. This paper aims to solve this problem by using thick-film technology, which utilizes a screen printing method to include ferrite thick film in the MPA structure as substrate overlay to help enhance the performance of MPA. Yttrium iron garnet was chosen as the starting ferrite nanopowders, and the preparation and characterization of the ferrite thick-film paste were carried out to investigate properties of the thick film. Results showed that the thick film showed moderate permittivity and permeability, which is suitable for MPA fabrication. The actual fabricated MPA with ferrite thick-film inclusion on FR4 substrate showed that the thick film improved the performance of MPA with low firing temperature of 200 °C. For MPA which is designed to work at 5.8 GHz, the return loss and -3-dB bandwidth improved 100% and 73%, respectively. In conclusion, ferrite thick-film inclusion in MPA fabrication has proven to improve the performance of the antenna in terms of return loss and bandwidth enhancement.

Discovery of carbon nanotubes (CNTs) was beginning of a revolutionary path for material scientists. CNTs extraordinary properties made this wonder material an important alternative for scientists in all fields; although utilizing CNTs were not as simple as synthesizing them. Ever since the discovery, numerous platforms for synthesis of CNTs have been investigated. Depending on the necessity of the application in which CNTs are exploited different quality, yield, chirality, size, and properties are required. Nowadays the fabrication process mostly relies on arc discharge, laser ablation and chemical vapor deposition (CVD). One of the major drawbacks in exploitation of CNTs is their tenancy to aggregate due to the weak van der Waals forces present as a result of sp2 hybridization of carbon atoms. Due to the extraordinary mechanical, electrical, optical, chemical, physical, biological, and other features of CNTs, scientists began to work on different methods to overcome aggregation during utilization of CNTs. Dispersion of CNTs has been done via several functionalization processes. Each of these techniques has their own functionality. Functionalization of CNTs depends on two central techniques, covalent and noncovalent modifications, which are essential, to achieve desired characteristics that can be applied in wide range of applications. Therefore, in this chapter we will try to explain the CNTs fabrication techniques as well as the methods that have been utilized to increase the purity and dispersion of CNTs.

In this work, a quick and effective method to synthesize carbon nanotubes (CNTs) is reported; a commercial microwave oven of 600 W at 2.45 GHz was utilized to synthesize CNTs from plasma catalytic decomposition of polyethylene. Polyethylene and silicon substrate coated with iron (III) nitrate were placed in the reaction chamber to form the synthesis stock. The CNTs were synthesized at 750°C under atmospheric pressure of 0.81 mbar. Raman spectroscopy and field emission scanning electron microscope revealed the quality and entangled bundles of mixed CNTs from which the diameters of the CNTs were calculated to be between 1.03 and 25.00 nm. High resolution transmission electron microscope further showed that the CNTs obtained by this method are graphitized. Energy dispersive X-ray analysis and thermogravimetric analysis revealed above 98% carbon purity.

Advances in the synthesis of carbon nanotubes (CNTs) have emerged as a result of the properties and potential application of carbon nanotubes. We demonstrated a simple approach of using domestic microwave oven with 600W at 2.45 GHz which was modified to produce CNTs from a carbon source on coated silicon oxide substrate. The Raman spectroscopy showed the graphitic nature of the obtained CNTs, with intensity ratio ID/IG calculated to be 0.92. Field emission scanning electron microscope (FESEM) reveals CNTs are produced on the substrate surface with outer diameter range of 11-44 nm and length of about 0.25 μm. HRTEM further confirmed the graphitic nature of the CNTs obtained. The purity of the nanotubes was analyzed with energy dispersive X-ray (EDX) which showed atomic weight of 98% carbon purity. This paper shows that domestic microwave oven can be used to synthesize CNTs with polymer as the carbon source via plasma catalytic decomposition which was found to be fast, economical and clean technique.

This paper presents results of study on Yttrium iron garnet (YIG) thick film paste using linseed oil as organic binder. YIG nanopowder is mixed with organic vehicle which consists of linseed oil, m-xylene and α-terpineol. Samples with different ratios of compositions are prepared to study the printability and adhesion properties of the paste. Paste samples were then screen printed onto alumina substrate, dried and fired at 300°C. Microscopic images of the samples were observed to determine most suitable ratio for producing YIG paste. Based on the results, YIG paste with 30 wt% ratio showed good adhesion to the substrate as well as having high dielectric property compared to pastes with lower powder ratio.

Highly graphitized nucleophilic group functionalized Multiwall carbon nanotubes are utilized to fabricate PDMS/FMWCNTs nanocomposites with low weight fraction (0.1 wt%). The effect of solvents on dispersion of FMWCNTs is studied. THF shows higher dispersion power in comparison with chloroform. The dielectric constant is measured using impedance analyzer in the range of 106-109 Hz. The result indicate, the dielectric property of FMWCNTs/PDMS nanocomposite could be manipulated with proper mixing techniques and adjustment of curing time.

Detection and quantification of biological and chemical species are critical to many areas of the life sciences and health care, from disease diagnosis to drug screening. Central to detection is the transduction of the signal associated with the sensing event. Advances in nanotechnology have led to the development of the silicon nanowire which is faster, smaller, greener and cheaper. These nanowires have a very narrow diameter similar to that of the chemical and biological species to be sensed making them perfectly suited for biosensing. The top-down fabricated silicon nanowires is used in this work due to its oxide-coated surface and ease of integration with other microelectronic components. Due to the ultra-small output signal of the nanowire, bulky equipments which are often time consuming and expensive are used for reading the signal. This work attempts to build a circuit that can be interfaced with the nanowire to make the signal readable hence the sensor will become portable thereby increasing its utility to being a point-of-care and field-testing device.