New strategies for the fabrication of transparent functional devices using invisible metal mesh electrodes, which is the new class of transparent conducting electrodes developed in this laboratory. Functional devices, particularly in the context of smart windows where fabricated using mesh as transparent electrode. The usage was extended to other devices suggest a defrosting and defogging windows, transparent supercapacitors, electrochromic supercapacitors and transparent photodetectors. These devices clearly demonstrates how metal mesh serves as inexpensive alternative for ITO films while having additional advantages such as high temperature attainability and flexible heaters with few second response times.