Cellulose nanocrystal/graphene oxide composite was reported as a humidity sensor in this study. The
composite film was fabricated using simple blending the materials followed by oven drying. The composite
film offers a unique advantages of cellulose combined with functionality of GO. It was capitalized to
design renewable, flexible and cheap humidity sensor. Performance of the composite film as a humidity
sensor was evaluated on the basis of relative capacitance change at different humidity level. Synthesized
composite film was characterized using scanning electron microscope, Fourier transform infrared
spectroscope, and X-ray diffraction. Environmental effect such as temperature was taken into account
on the sensor performance. The sensing mechanism is explained on the basis of presence of hydrophilic
functional groups in the composite. The linear and fast response of the developed sensor is advantageous.