An AC-based GaN blue light-emitting diodes (LEDs) with different designs (series and Wheatstone Bridge configurations) were successfully fabricated and demonstrated at wafer and chip level under CSIR network (R-Nano) programme. In the first design, 42 micro-LED chips were connected in a series for a high voltage operation, where the size of each chip was ~ 250 [...]
MEMS-based gas sensors being miniaturised have various advantages such as low power consumption, robust and stable electrical properties. These gas sensors have three main components namely micro-heater, interdigitated electrodes and sensing film. Micro-heater as the important part of the gas sensor device decides the power consumption of the gas sensor. Metal oxide based gas sensing platform [...]
A MEMS-based bulk micromachined piezoresistive accelerometer was designed and fabricated. The accelerometer is a quad-beam suspended structure, which is realised by a combination of wet and dry bulk micromachining techniques. The fabrication process of the accelerometer is CMOS compatible. Image of the fabricated accelerometer is shown in Fig. 1. The accelerometer has been designed for low-g [...]
Fluid-FET: The Fluidic-Field Effect Transistor (Fluid-FET) has a nano-dimensional fluidic channel, connecting two fluid reservoirs and is capped with high-quality thermal SiO2 (i.e. low surface charges compared to PECVD SiO2) which is used as gate oxide; analogous to a channel between source-drain of a conventional Field Effect Transistor (FET). The ionic conductance modulation in the range [...]
Measurement of viscosity plays an important role in the quality control at various research and development stages in a lab as well as a wide range of industries including food, chemical, healthcare, pharmaceutical, petrochemical, cosmetics, paint, ink, coatings, oil and automotive industries. A portable passive and electronic version of micro-viscometer is developed (Fig. 1) which has [...]
A pressure sensor for Micro Air Vehicle (MAV) application was developed. The pressure sensor structure consists of four diffused polysilicon piezoresistors placed on a diaphragm fabricated by bulk micromachining and connected in Wheatstone bridge. Pressure sensors are fabricated for a pressure range of 0-1.1 bar and the meander shaped piezoresistors are placed at optimized highstress regions. [...]
Under DST (India)-Japan Society for the Promotion of Science (JSPS) collaborative project, a green gap broadband emitter has been developed to achieve a broad emission in the yellow-green region for GaN-InGaN LEDs, using single InGaN/AlN nano-disk, sandwiched between n-GaN and p-GaN epitaxial layers grown by MOCVD. Self-assembled InGaN/AlN structure was grown on a single-sided polished c-plane [...]
An AC-based GaN blue light-emitting diodes (LEDs) with different designs (series and Wheatstone Bridge configurations) were successfully fabricated and demonstrated at wafer and chip level under CSIR network (R-Nano) programme. In the first design, 42 micro-LED chips were connected in a series for a high voltage operation, where the size of each chip was ~ 250 [...]
Under CSIR network (R-Nano) programme, various photonic crystal (PhC) structures and waveguides including line-defect, coupled cavity and ring-type PhC structures on silicon-on-insulator (SOI) substrates were designed using finite difference time domain (FDTD) method. These structures could be used as a refractive index based sensor platform for chemical and bio-chemical sensing applications. Fig. 1 shows one of [...]
GaN-based high electron mobility transistor (HEMT) was developed under a CSIRsponsored project for bio-sensing applications.The device has a source-drain distance (Lsd) of 50 μm and a unit gate width of 2x125 μm and 2x50 μm. Various gateless and gated devices having Lsd variations from 7.0 μm to 50 μm are electrically tested to check the maximum [...]