Challenges exist in the material selection to maintain the conformal contact with the skin . For example , dead cell efflux through the skin may interfere with the measurement data . Another challenge that limits the adoption of electronic tattoos is that long time - wear over the skin may cause ' irritant ' dermatitis . One potential direction in the development of electronic tattoos is the use of surgical - grade stainless steel and its alloys that can provide high hypoallergenic features .