Neuromodulation treatments are based on the functional interface between the brain and man-made electrodes. Chronic inflammation around the implant, however, occurs as a result of mechanical mismatching between soft brain tissue and the stiff metallic electrode. After water uptake, cellulose films should prevent encapsulation of the electrode. In this work, we reinforced cellulose films with silk fibre networks, improving tear strength by a factor of four to seven and maintaining flexibility, characterised by an elastic modulus between 100 and 200 MPa. Whereas sputtered gold on flat films exhibited restricted adhesion, micro-patterning guaranteed reasonable adhesion of nanometre-thin gold to cellulose substrates. Micro-patterned cellulose films coated in 80 nm-thin gold retained conductivity for strains as large as 30%, while sheet resistance increased by a factor of about 30. Fabrication of the biocompatible electrodes is efficient and compatible with large-scale production.