While visiting your injured squad member, overhear the asari standing at the entrance of the right Lab Services in the hospital. You can also acquire it if you find the Biotic Amp Interfaces first while doing the mission Grissom Academy: Emergency Evacuation.
Note: This mission must be completed before completing Priority: Tuchanka as it will be the last opportunity for the player to visit the Citadel before Priority: The Citadel II, after which it will no longer be available.
The Biotic Amp Interfaces can be found during the mission Grissom Academy: Emergency Evacuation. They are found on a computer terminal in an otherwise empty corridor, just after the two major fights in the atrium.
Simply collect the interfaces and return them to the asari on your next visit to the hospital and you will be rewarded with 5 Reputation, 30 experience and 1,000 credits. The Citadel Defense Force War Asset is updated as well.
If you missed them in the Academy or get the mission after completing the Academy, they can be bought from the Spectre Acquisition terminal in the Spectre Office at the Citadel Embassies.