With fast development of flexible devices, soft materials,
polydimethylsiloxane (PDMS), have been paid much attention
and have been used to fabricate various components
[6–9]. In our previous work, the fabrication of PDMS
microlens arrays using replica molding had been reported
[7]. Therefore, we hope to develop additionally a reflective
function under analogous fabrication processes. Although
one of most direct approaches is that a metallic film deposited
on the PDMS surface, a PDMS layer covered a metallic
film would form spontaneously wavy structures on the
PDMS surface due to the different contraction rates of
cooling between the metal film and the PDMS layer [10].
These wavy structures on PDMS surface would cause the
diffusion of light as light irradiated this surface. Therefore,
metal films would easily crack under a small physical deformation
due to the different ductility between the metal film
and the PDMS layer. Hence, the secondary challenge is
how to reflect light without metal films covered on the
PDMS surface.