Piezoresistive properties of sulfur-doped MDMO-PPV films

The piezoresistive characteristics of a series of sulfur-doped poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) thin films were investigated using indium tin oxide and tungsten as electrodes. The film exhibited optimal piezoresistive performance when the mass ratio of sulfur to the host MDMO-PPV material was 1:10. Within the measurement range of 0–1468 kPa, the calculated piezoresistive coefficient reached approximately 5 Pa−1. This study demonstrates that introducing an appropriate amount of sulfur into MDMO-PPV films can effectively enhance their electrical conductivity, thereby increasing the current density, while preserving the film's elasticity and structural stability. By optimizing the sulfur-to-MDMO-PPV mass ratio to 1:10, the film's performance was significantly improved, achieving an excellent balance between mechanical flexibility and electrical conduction. Consequently, films with this specific doping ratio display excellent overall characteristics compared to their undoped counterparts, indicating promising potential for applications in tactile sensing technologies.