In addition to microdrives, chronic implants with silicon probes require a protective structure (head gear). The head gear serves multiple purposes:

• Protect the implant site and microdrives/probes from animals and debris, by providing a physical barrier
• Hold the high-density connectors (or headstages, for Neuropixels and Cambridge Neurotech mini amps) and decouple them physically from the microdrives (in the following, we will use Omnetics connector, which are still the most common ones, as a blanket term for all high density connectors, head stages, or EIBs that are the interface between the flex cable on the probe and the tether cable leading to your recording system)
• (optionally) Improve recorded signal by acting as a Faraday cage (less important for the nowadays common neural data acquisition systems that digitize the signal very close to the electrode)
• (optionally) Provide possibility for head fixation of the animals

The head gear that is typically used with the R2Drive and 3Drive is based on a protective copper mesh construction originally by Vandecasteele et al [1]. This solution (which we just refer to as copper mesh) is still the gold standard, as it allows for a very flexible way of realizing even complex implants with multiple drives (see, for example, [2, 3] who implanted three 3Drives simultaneously using this approach). No matter which of our head gear solutions you choose, we do recommend you familiarize yourself with the original JoVE protocol, as it helps in understanding the purpose and underlying ideas of the system.

However, the flexibility of the copper mesh comes at the cost of complexity – the implant has to be built/finalized during surgery, extending surgery times by up to an hour (for experienced users) or more. In addition, the Omnetics connectors are secured onto the copper mesh by soldering, which can be an additional hurdle.