Colloidal hydrogel microlenses

The creation of microlenses from hydrogel microparticles is demonstrated. The fabrication of substrate-supported microgels is performed using electrostatic interactions between aminopropyltrimethoxysilane-functionalized glass substrates and acrylic acid groups present on the microgel surface. The lensing ability is illustrated by imaging a photomask through each of the microgels present on the surface (see Figure).