3D-printed microelectronics for integrated circuitry and passive wireless sensors

Three-dimensional(3D)additive manufacturing techniques have been utilized to make 3D electrical components,such as resistors,capacitors,and inductors,as well as circuits and passive wireless sensors.Using the fused deposition modeling technology and a multiple-nozzle system with a printing resolution of 30μm,3D structures with both supporting and sacrificial structures are constructed.After removing the sacrificial materials,suspensions with silver particles are injected subsequently solidified to form metallic elements/interconnects.The prototype results show good characteristics of fabricated 3D microelectronics components,including an inductor–capacitor-resonant tank circuitry with a resonance frequency at 0.53 GHz.A 3D“smart cap”with an embedded inductor–capacitor tank as the wireless passive sensor was demonstrated to monitor the quality of liquid food(e.g.,milk and juice)wirelessly.The result shows a 4.3%resonance frequency shift from milk stored in the room temperature environment for 36 h.This work establishes an innovative approach to construct arbitrary 3D systems with embedded electrical structures as integrated circuitry for various applications,including the demonstrated passive wireless sensors.

Passive wireless smart-skin sensor using RFID-based folded patch antennas

Folded patch antennas were investigated for the development of low-cost and wireless smart-skin sensors that monitor the strain in metallic structures.When the patch antenna is under strain/deformation,its resonance frequency varies accordingly.The variation can be easily interrogated and recorded by a wireless reader.The patch antenna adopts a specially chosen substrate material with low dielectric attenuation,as well as an inexpensive off-the-shelf radiofrequency identification(RFID)chip for signal modulation.Since the RFID chip harvests electromagnetic power from the interrogation signal emitted by the reader,the patch antenna itself does not require other(internal)power sources and,thus,serves as a battery-less(passive)and wireless strain sensor.In this preliminary investigation,a prototype folded patch antenna has been designed and manufactured.Tensile testing results show strong linearity between the interrogated resonance frequency and the strain experienced by the antenna.Through experiments,the strain sensing resolution is demonstrated to be under 50με,and the wireless interrogation distance is shown to be over a few feet for this preliminary prototype.

A Design of Remote-Controlled Chalkboard Eraser

Chalkboard erasers that are commonly used in many schools and education organizations have the poor ability in removing the dust off the chalkboard and collect them. The dust that is not collected will be taken into human bodies via inhalation, which will lead to respiratory diseases. Therefore, it is crucial to design a chalkboard eraser that can collect the dust effectively. If the eraser can be controlled both remotely and manually by people, it can further reduce the amount of dust taken in by human bodies. To achieve remote control, a micro-controller is needed to transfer the infrared radiation (IR) into signals that can control electric motors to move around on the chalkboard. Furthermore, the microfiber is also used as the cleaning material to improve the performance of dust cleaning and collecting. A vacuum pump is needed to create negative pressure between the eraser and the chalkboard so that the eraser can stick to it. The result shows a stronger ability in removing and collecting dust. With the help of the Arduino UNO board, the remote control is successfully achieved, and the eraser can move on the chalkboard freely according to the order.

Smart Building Design to Improve the Energy Consumption at an Office Room

Buildings are becoming smarter as a result of a variety of advanced technologies that enable energy management, optimal space utilization, and smart surveillance for safety, among other things. Energy-efficient smart building ideas and execution are of great interest and top priority due to the building’s occupants’ misused and high-power consumption. This paper addresses the design and execution of an energy management system that includes a solar power system for generating power for the building’s needs and a PIR-based automation system for efficient power use. This project was carried out at the Military Technological College (MTC) in Muscat, in the system engineering department’s offices. This project seeks to generate power for the building’s energy needs using solar photovoltaic panels and reduce energy consumption within the office using a PIR-based automation system. The results demonstrate that after the breakeven point (the time it takes to recoup the initial investment), it can provide power to the building for another 17 years. The calculations and practical results presented in this study approve that the system is extremely helpful.