Abstract: The use of DNA or other charged biomolecules for data storage can include the use of devices to manipulate the biomolecules in solution, e.g., to store and later to selectively read out selected samples of stored biomolecules. Systems and methods provided herein facilitate the electrical manipulation of DNA or other charged biomolecules for data storage or other applications by applying voltages to sets of electrodes arranged along the length of channels of microfluidic devices. The magnitudes and signs of the applied voltages can be controlled to collect DNA into a channel, to retain the collected DNA in the channel for later use, and then to expel the DNA from the channel for readout (e.g., by a pore sequencer integrated into the same microfluidic device as the channel). Such storage channels can have rectangular cross-sections or otherwise include electrodes having substantially planar geometry.