Flow cell with one or more barrier features

An apparatus, comprising:

• (a) a flow cell body defining one or more flow channels and a plurality of wells, each flow channel of the one or more flow channels to receive a flow of fluid, each well of the plurality of wells being fluidically coupled with the corresponding flow channel of the one or more flow channels, each well of the plurality of wells defining a corresponding depth;
• (b) a plurality of electrodes, each electrode of the plurality of electrodes being positioned in a corresponding well of the plurality of wells, the plurality of electrodes to effect writing of polynucleotides in the corresponding wells of the plurality of wells;
• and
• (c) a temperature gradient generator, the temperature gradient generator to provide a temperature profile that varies between the plurality of wells.

A method comprising:

• flowing fluid through a flow cell, the fluid containing nucleotides, the flow cell comprising a flow cell body defining one or more flow channels, each flow channel of the one or more flow channels to receive a flow of fluid, at least one of the one or more flow channels having:
• (i) a floor,
• (ii) a plurality of wells defined as recesses in the floor, each well of the plurality of wells being fluidically coupled with the corresponding flow channel of the one or more flow channels, the floor of the flow channel of the one or more flow channels defining interstitial spaces between adjacent wells of the plurality of wells, and
• (iii) a plurality of barrier features above the wells of the plurality of wells or in the wells of the plurality of wells;
• activating electrode assemblies at bottom regions of each well of the plurality of wells to generate machine-written polynucleotides within each well of the plurality of wells, the machine-written polynucleotides representing stored data;
• and
• activating the plurality of barrier features to reduce optical cross-talk between adjacent wells of the plurality of wells.