Electrochemical sensing based on printable temporary transfer tattoos

基于可印刷的电化学传感
临时转移纹身

Electrochemical sensing based on printable
temporary transfer tattoos

on the insulator design to define the working and counter electrode geometry. Finally, an Ag/AgCl-based
ink was employed to define the connection points as well as the reference electrode. After each printing
process, the patterned substrate was cured in a temperature-controlled convection oven (SalvisLab
Thermocenter, Renggli AG, Industrie-Ost, Switzerland) at 60 °C for 40 min and finally cut into individual
sensor tattoos for single use. In order to conduct electrochemical experiments, a tattoo pattern containing
a circular working electrode was designed and possessed a 3 mm radius. In order to increase the tensile
strength of the printed electrodes, 100 mg of chopped CFs were dispersed in 30 mL of ink and
homogenized thoroughly. It should be noted that the loading level cannot be adjusted arbitrarily high.
Exceeding the 0.04 % level compromised the viscosity of the ink and the ability to generate well-defined
printing patterns. Therefore, the 0.04 % CF reinforcement level was employed in all the studies.
Fig. S1: Transfer of the T3 sensor onto the epidermis: (a) The protective sheet is peeled from the
patterned T3 paper. (b) The paper is flipped and applied to the skin and subsequently dabbed with water
(c). Finally, the paper is gently removed (d), exposing the sensor contingent.
Fig. S2: Photographic evaluation of the CF-reinforced T3 sensor on human skin during (a) pinching and
(b) stretching.