A photoassisted chemical bonding method was used to accurately position diatom frustules into complex microscale patterns on a PDMS surface. The micropores and fine features of the diatom frustules were perfectly preserved because neither pressure exerted on diatoms nor etchant contacted in the whole process. This method has the potential to enable diatom device applications utilizing the functionalized frustules especially for biosensors, biodetection chips, and microfluidic chips.