6 - Shielding the drive

Created by Jakob Voigts, last modified on Jun 12, 2015

Attaching the housing/shield

 

Print templates on standard overhead transparency sheet. If your EIB does not use a central optical fiber ferrule, a different placement of the mounting hole might be required.

Glue aluminium foil to the transparency sheet with epoxy for the cone part.
Use plain transparency sheet for the cap part.

Cut out parts using scissors, and glue with epoxy.
Clamp the parts with a hemostat while the epoxy cures.

If there are gaps left in the shield cone, fill them in with a second, thin layer of epoxy.
 

For cap: attach optical ferrule cap (different depending on EIB type) to cap. This securely holds the cap in place and allows easy removal and re-attachment.

Alternatively, or in addition, use small pieces of adhesive tape to attach the cap to the drive after implant. We are getting the best results with kapton tape. Use new pieces of tape each time and make sure all edges of the tape are fully adhering.

Guide the ground wire through the bottom opening of the protective shield cone and attach cone with epoxy. Make sure there is a strong bridge of epoxy between the side of the drive body and the cone. Use multiple layers of epoxy if needed. Take extra care not to touch and bend electrodes with the protruding end of the ground wire.

Use conductive epoxy to connect the shield wire to the drive shield. Secure with additional layer of regular epoxy.

Apply small amount of mineral or silicone oil to the springs where they meet the screws.

If corrosion is a concern in your application (especially for long recording durations), also add a light oil film along the arms of the springs. This will lead to much more dust/hair buildup inside the drive, but will reduce corrosion.

At this point the electrodes can be lowered somewhat and gold-plated if desired. After gold-plating and impedance measurement, the gold pins should be secured to the eib with a thin layer of 5-minute epoxy. Use a thin wire or similar tool to distribute the epoxy between the pins so it makes good contact with the EIB and the pins, otherwise its possible that the epoxy stays on top of the pins and tetrode stubs, especially on the dense small 64ch EIBs. When re-using the EIB for another drive later, this epoxy can be removed easily by leaving the EIB in ethanol for a few days. This softens the epoxy so it can be easily removed. Also make sure to remove the epoxy from the omnetics connector(s), also under the solder feet, and re-epoxy the connector.

The drive is now ready to implant.