A facile, green procedure is proposed to synthesize single-crystal gold microflakes with planar area up to 10(4) mu m(2). This unprecedented dimension offers new possibilities in designing flexible conductive films with tunable strain-dependent conductivity, that can be exploited in strain/force/vibration sensing devices. By using top-down micro-/nanofabrication techniques, these materials may further find use in single-crystal electronics and plasmonic applications.