Yes. If you try to design any device to capture all the molecules like that and extract their energy, you'll find that just as often your device dislodges a water molecule the other way, back into the pool and losing energy. Thus although You aren't the first to invent the Brownian ratchet.

The device shown in the OP appears to allow for a sustained thermally-driven energy transfer one way or the other depending on the bit value ou are sending.