Micro- and nanopatterns of polymer brushes (see Figure) are fabricated using a "top-down/bottom-up" approach. A silicon surface is patterned with gold using lift-off electron-beam lithography ("top-down"), and the resulting pattern is then amplified by surf ace-initiated atom-transfer radical polymerization ("bottom-up") of N-isopropylacrylamide from an immobilized thiol initiator.