Unmanned Aerial Vehicles (UAVs) are increasingly used to deliver items and gather information in remote areas. As a result, UAVs suffer from ice accumulation on their wings, which drastically affects their flight. However, the UAV industry is still relatively young and, thus, commercial solutions for deicing on UAVs are limited. The use of carbon fiber composites is becoming increasingly ubiquitous for UAVs as well as many other industries such as military, construction, medical, automobile, sporting goods and aircraft systems. Carbon fiber is commercially available in various forms, including single yarns, braids and weaves, which are similar to traditional textiles. This paper presents a method to create a self-heating composite structure that can be integrated into UAV wings for de-icing by exploiting the thermal and electrical conductivity of carbon fiber. Extrusion printing is used to fabricate electrical contacts directly on the carbon fiber weave. Extrusion printing on textiles faces multiple challenges that are overcome in this paper. A method is presented to extrusion print conductive paste on textiles. Specifically, carbon fiber weaves. This manufacturing method is employed to fabricate carbon fiber-based heating devices, and they are characterized electrically and thermally.

This paper presents a complex microstrip patch antenna design for Ku-band satellite communication applications. FR4 and RogerRT6002 have alternatively been used as substrates having dielectric constant of 4.4 and 2.94 respectively. The patch ground and feedlines are made of copper. The proposed antenna is unique in shape with rectangular slots. The performance of the antenna has been analyzed in terms of far field gain. The most significant results were obtained using FR4 substrate, which gave a gain of 7.88 dB, at 11.32 GHz and a reflection coefficient of-10.48 dB. The final microstrip patch antenna design was simulated, built and tested. Simulated and measured S11 frequencies perfectly match at 11.32 GHz with simulated and measured magnitudes of-10.48 dB and-29.64 dB respectively.

No abstract

No abstract

Structural Health Monitoring (SHM) uses sensors in advanced engineering structures to evaluate integrity and detect damage or deformation affecting structural performance, e.g. cracks, holes, or corrosion. Carbon fiber (CF) textile composites are commonly used to reinforce structures such as aircraft, vehicles, or bridges due to their high tensile strength to weight ratio, chemical resistance, and thermal and electrical conductivity. Printing electronics on textiles is a scalable manufacturing technology combining the physical properties of textile materials with the added functionality of electronic elements making them self-sensing. Extrusion printing is a contactless digital printing method to print electrical conductors and passive circuit elements. This paper proposes to combine conventional CF composite manufacturing processes with printed conductors to create self-sensing CF textile composites. Damage is sensed by measuring resistance changes in a CF sheet. Contacts are extrusion printed directly on woven CF sheets using silver flake ink. A multiplexed Kelvin Double Bridge circuit is the read-out interface. This allows small resistance changes due to damage to be measured in a four-point configuration. The circuit is connected to the printed contacts on the CF sheet through multiplexers to detect damage in different locations. This 2D digital sensor can detect the location and size of damage holes for SHM. The resolution of the sensor is controlled by the location and spacing of the silver electrodes, which were studied experimentally and by simulation. The resolution is 26 mm in the current direction and 16 mm in the orthogonal direction. The threshold of detectable damage is 4 mm2. Simulation of the sensor as an isotropic 2D conductor shows good agreement with experimental results for the orthotropic fabric. The resultant sensing device could be integrated into many composite structures as one of its layers or simply printed on the surface to create smart structures.