This thesis describes the work on three categories in top-down approach in nanotechnology: tip-based nanofabrication tools, study on properties of 2D material, graphene, and making devices based on graphene. After describing the working principals of nano optical ruler imaging system (NORIS), modification and improvement of NORIS are described. Then, the NORIS hybrid with commercial nano-imaging tool, the Veeco 3100 AFM/STM tool is described. A wireless image transmission by CC2530 chip for low-noise displacement measurement in this hybrid is described. Next, the piezoresistivity and gauge factor of graphene/silicon-nitride membrane composite are measured and found to be exceptionally high compared to the currently utilized piezoresistive materials such as poly-silicon, and other graphene piezoresistivity results. Fabrication of silicon-nitride membrane with graphene samples, transferred on top of this device is described, followed by describing the measurement setup for piezoresistivity measurement of graphene/SixNy stack. With ultra-high piezoresistivity, measured for this stack, fabrication and measurement of strain gauges is described. Next, scanning probe based nano etching of graphene samples is introduced. Subtractive mass removal using the tip-based graphene etching is used to tune micro electro mechanical (MEMS) resonator with 7.6ppm resolution.