An example flow cell includes a patterned substrate having an active region and a bonding region that at least partially surrounds the active region. The active region includes first depressions defined in a layer of the patterned substrate, surface chemistry positioned in the first depressions, and first interstitial regions surrounding the first depressions. The bonding region includes second depressions defined in the layer and second interstitial regions surrounding the second depressions. An adhesive is positioned over the second depressions and over the second interstitial regions. A cover is attached to the adhesive such that a flow channel is defined between a portion of the cover and the active region.