Flexible multifunctional electronic devices are of high interest for a wide range of applications including thermal therapy and respiratory devices in medical treatment, safety equipment, and structural health monitoring systems. This paper reports a scalable and efficient strategy of manufacturing a polyacrylonitrile-carbon nanotube-polyacrylonitrile (PAN-CNT-PAN) robust flexible platform for multifunctional electronic devices including flexible heaters, temperature sensors, and flexible thermal flow sensors. The key advantages of this platform include low cost, porosity, mechanical robustness, and electrical stability under mechanical bending, enabling the development of fast-response flexible heaters with a response time of ≈1.5 s and relaxation time of ≈1.7 s. The temperature-sensing functionality is also investigated with a range of temperature coefficient of resistances from −650 to −900 ppm K −1 . A flexible hot-film sensing concept is successfully demonstrated using PAN-CNT-PAN with a high sensitivity of 340 mV (m s −1 ) −1 . The sensitivity enhancement of 50% W −1 is also observed with increasing supply power. The low cost, porosity, versatile, and robust properties of the proposed platform will enable the development of multifunctional electronic devices for numerous applications such as flexible thermal management, temperature stabilization in industrial processing, temperature sensing, and flexible/wearable devices for human healthcare applications.