elastic head caps: Electro-Cap, g.GAMMAcap, etc.

edited August 2015 in Headware
Hey everyone, 

I just purchased the starter Arduino kit and I was wondering if anyone knew of an electrode head cap I can use with this kit.



  • edited October 2014
    Hey guys,

    I am working with some classmates on a senior design project and we just put in our order for an OpenBCI kit! We are developing a prosthetic limb that we are looking to control with our mind.

    We are extremely excited to work with this product and hope we can rely on this community for support (both emotional and technical!). Although we have a kit coming in with a full electrode array, I was wondering whether there were any suggestions regarding the usage of a cap to embed the electrodes in.

    In general, any resources that would help us get better orientated with this work and prepare us to hit the ground running when the kit comes in would be greatly appreciated.
    Thank you in advance and I look forward to collaborating with you all.


  • brainbrain Canada
    edited October 2014
    Hello Mohit,

    This is a question I’m facing as well: the OpenBCI team is working on a modular 3D printed headset for the OpenBCI, but they don’t seem (?) to have released the files for the design yet.

    In the mean time, you could consider using a standard electrode cap, although they tend to be expensive. Chip of EEGHacker (and OpenBCI researcher-at-large) uses this cap from Biopac: http://www.biopac.com/electrode-cap-system-touchproof You’ll need to request a price quote — I guess they vary the price based on what institution you’re from, if any — but Biopac seems to be a well-respected provider of EEG supplies.

    Alternately, if you’re not using many electrodes at once you may be able to just put the cups on with the 10-20 paste and secure them with a headband of some sort — at least until the headset design is done.

    I have found very little of use to amateur enthusiasts. The one resource I can recommend is Chip’s EEGHacker blog, which has a lot of stuff about the OpenBCI (including actual tests, since he can get his hands on the prototypes). I’m also working on a 6-post series on the background information needed to use the OpenBCI effectively, which I’ll be publishing on autodidacts.io

    Good luck with your efforts!

  • edited November 2014
    Thanks @brain - I already saw that thread and I was wondering if there were alternatives to that...as the cap itself costs more than $300.  I really want to know which one they are using in the intro video.
  • Yeah, they’re pricey! What’s your intended use? I’m planning to just use plain electrodes and the 10–20 system until the files for the 3D printed headset are updated for the production boards. @Conor would be the one to ask about the cap in the video, though the OpenBCI team is probably pretty busy shipping the boards out ATM.

    Good luck!
  • @brain - I'm trying to run some tests for the company I work for to see how viable the data that this thing gathers is.  We will print out the model when it becomes available but it would also be nice to use something that's not so rigid... 
    How are you securely attaching the electrodes to your head in the 10-20 system?   
  • wjcroftwjcroft Mount Shasta, CA
    The caps are $260 from the actual manufacturer, Electo-Cap.  Biopac (mentioned on other posts) is just a distributor;  so prices slightly inflated there.


    These can only be worn for 30 mins to an hour before your head starts to hurt from the compression.  I will post some saline system links shortly.   Which avoid use of paste or gel.
  • @wjcroft - Thanks! So what function does the cap exactly serve?  Is it to simply hold all the electrodes in place or does serve a greater purpose?
  • edited November 2014
    When V3 comes out, I'll start printing them for people. $50 each including shipping. All you have to do is buy your own electrodes.

    @pwewegama They're just to hold the electrodes in place and to directly interface with the BCI unit in the body of the cap.
  • wjcroftwjcroft Mount Shasta, CA
    The Electro-Caps do not "directly interface with the BCI unit in the body of the cap".  They terminate in a ribbon cable which is about 4 feet long.  This cable has a DB25 connector with the pinouts for all 19 channels of the 10-20 map, plus a ground lead on the midline.  If you order the Lexicor style caps then the ribbon cable also brings out two drop leads, one for each ear reference. Electro-cap sells the ear clips which plug into these drop leads as a separate item.

    Adapters are available if needed to convert the DB25 to touchproof DIN connectors.


  • I stand corrected regarding the OpenBCI unit as I don't own one. I just use commercial medical EEGs.
  • edited May 2015
    Is it possible to just purchase the cap and use the OpenBCI supplied electrodes with it?

    Also, where do you get the DB25 to touchproof connector adapter?

  • DonReedDonReed Europe
    edited May 2015
    I want to do neurofeedback and everything I need is in place (OpenBCI, electrodes, conductive paste), except for a way to keep those electrodes on my head. Doing all this work (contacting the seller to request quotes, etc) just to pay 200$-300$ (!) in order to have a way to keep electrodes on your head seems preposterous. Is there any simpler way to attach electrodes to your head? Some homemade solution like poking holes in a swimming cap / winter hat and then duck taping electrodes there?

    Also when they will design the 3D printable headset, how mere mortal consumers living in different parts of the world (e.g., I live in Europe, but might go to Asia for a period of time in near future), who have no access to a 3D printer will be able to buy that headset? Are there any estimates on what price range mere mortal consumers can expect and whether they will even be able to get that headset without a 3D printer?
  • wjcroftwjcroft Mount Shasta, CA
    edited May 2015
    @teolivier and @DonReed , hi.

    There are several other threads you may want to look at regarding 'Headware'. Look at that category in the list on the right column and also take advantage of the search box.

    First have a look at the g.tec GAMMAcap, shown here,


    This is a relatively inexpensive cap (~ $230) with holes at all the 10-20 locations. The 3D printed holders shown there can allow use of the supplied gold electrodes and a conductive gel that you inject through the holes. The GAMMAcap can also be used with the dry electrodes shown on this thread,


    Also look on that thread for the velcro strap based 'headsets', consisting of punched holes. Also see the BrainNet webs on that same thread; about $30 with holes at 10-20 points. Yet another velcro approach is here,


    As you can see in some of the tutorial docs, it's common to use a simple elastic headband to stabilize electrodes located at the Fp1,2 T3 T4 O1 O2 etc. You actually do not NEED any bands if you have decided to use the standard paste approach. The paste holds on just fine and is used by countless neurofeedback practitioners.


    If you have questions on the printed headsets, please post on the appropriate thread,




  • edited May 2015
    I want to know which EEG caps are suitable to be used with Open BCI electrodes. and what are the specifications of these caps.Does OpenBCI have any collaboration with the EEG cap distributors?
  • wjcroftwjcroft Mount Shasta, CA
    @Ghina , I merged your question into this existing thread. Please see the post on May 4, which contains a number of links. There is a discount on the FRI velcro band systems (in dry-active thread.) The BrainNet web is also very inexpensive.

  • ShalomItamarShalomItamar Israel
    edited June 2015

    Where i can get helmet to fit all heads and easy to use, anyone know?
    I am new to all of these and maybe it is a silly question but it can be very helpful for me to get started.


  • wjcroftwjcroft Mount Shasta, CA
    @Shalomltamar , hi. I merged your question into this existing thread. Please see the post on May 4, which contains a number of links.
  • edited June 2015
    Anyone have any comments on the following type of cap?
    You can find this by searching ebay for "eeg cap".  They are selling for around $15.
    They look pretty cheesy, but then again if they work well then it would be well worth it.

  • wjcroftwjcroft Mount Shasta, CA
    edited June 2015
    Jake, that style of 'cap' is in more wide use in Asia and Europe. The elastic cords mate with electrodes that are called "net and post" or "post and bridge". So you'd need to either pickup the matching electrodes or hack together something on your own. While this system is used with the 10-20 points, you have to eyeball or measure the spacing yourself. Here's some more photos of systems showing the matching electrodes (two styles).


    The electrodes shown there can also be used without paste, using saline solution instead soaked into the pads. Page below shows other related "head net" systems using saline. As well as the velcro idea on the main page.


    My take is that the g.tec g.GAMMAcap (~$230) or BrainNet (~$30) are easier to use. This Asian net system also requires the chin strap. Which might be comfortable for short sessions.

  • Which electro Caps are compatible with OpenBCI? 
    Are this ones?
  • biomurphbiomurph Brooklyn, NY
    Yes, That cap is one that we have used with OpenBCI many times.
    We ship each kit with a set of touch-proof connectors, so that our device can connect to just about any electrode or cap on the market that uses touch-proof connectors.
  • wjcroftwjcroft Mount Shasta, CA
    @SirLouen , hi.

    I just merged your question into this previous thread on caps. Also checkout the g.tec g.GAMMAcap which is in the same price range as the Electro-Cap. ($230). Advantage of the g.tec cap is that it can be used with the FRI dry sensors. Or @jfrey 's printed adaptors (see posts above). With the Electro-Cap you would always need to inject the gel. The g.tec cap would also be compatible with the dry sensor combs from Cognionics (see dry sensor thread.) I think some folks have gone that route; though the Cognionics combs are hugely more expensive than the FRI.


  • wjcroftwjcroft Mount Shasta, CA
    edited November 2015
    The next couple posts were created from comments split from: Spiderclaw V3 (aka Ultracortex).

    [I still desperately want fabric headwear for sleep studies that'll use dry electrodes which I can hook up to the OpenBCI board. Unfortunately my budget is pretty limited since the original hardware and headwear were a stretch. Any tips on cheap fabric headwear are much appreciated.  -- Corey]


    Cool Youtube there on your Ultracortex, Corey.

    re: fabric caps. See the links on this post,


    The Brainnet is about $30. g.GAMMAcap ~ $230. The FRI velcro straps with punched holes. The strap material is Velcro One-Wrap, 3/4" width.


  • Thanks. I've considered both of those options but wasn't thrilled with either. The Brainnet seems cheaply done and the g.GAMMAcap is a bit too much. I was hoping to find something for $100 that wouldn't need the gel so it'll last for regular use.

    Looking at the g.GAMMAcap it was kind of hard to tell how the electrodes worked otherwise it looked great. Perhaps I'll just have to wait a bit for some cheaper sleep headwear.
  • wjcroftwjcroft Mount Shasta, CA
    The third option was the velcro straps. You can use your own One-Wrap material and punch your own holes for the FRI combs. With enough cross straps (no holes), and even a chin strap, you could make a custom soft 'headset' that does not move around and is comfortable for sleep.

    With both the g.GAMMAcap and the strap holes, the 'hole' is what is provided. The comb would be inserted from the 'inside' of the cap, then clipped on with the FRI clips on the 'outside' of the cap or strap. Depending on the hole size, you may also need to fit some sort of plastic washer over the comb connector before attaching the clip. This would prevent the comb from pulling through the hole, if the hole was too large.

    But I don't think that is the case with the g.GAMMAcap, the holes there are reinforced with stitching. Washers, if needed could be purchased or made from plastic milk carton (HDPE) sheet. 

  • edited December 2015
    What about these?

    I am attempting to use the OpenBCI hardware to build a sleep-study sort of cap to augment my cpap mask so I just put them both on every night, so it does need to be really comfortable.

    I am looking to create (with this community's help) a headware configuration that can be added to cpap masks inplace of existing neoprene straps that most use.  That could be used to wirelessly feed an Android app raw data to help qualitatively analyze (somehow) your sleep and then hold that up against other journalled daily activities to understand what is causing bad sleep patterns, and if the cpap device is doing its job.

    Maybe it could just help the 18million+ people and the other 4% of this country's undiagnosed sleep apnea patients.  Beats wearing a stupid (and dumb) Fitbit that uses actigraphy to sort-of guess which stage of sleep you are in.  Not nearly granular enough for me.

  • wjcroftwjcroft Mount Shasta, CA
    Karl, hi.

    Fun coincidence, your first name is the same as Karl @KZurn, who sells those dry sensors at FRI. There is a whole thread on the dry electrodes. Those are the same sensors used in the Ultracortex. 

    Also see this project on the Community page,

  • alexandreDalexandreD Paris
    edited June 2016
    Hi everyone,

    I am also thinking about a system that is usable during night so looking for a head cap suitable for that purpose.

    Do you know if such head cap


    could be usable with openBCI electrodes ?

    thank you

    from France
  • wjcroftwjcroft Mount Shasta, CA
    edited June 2016
    @alexandreD, hi. That looks like a decent cap. It 'might' work if you figure out a "fixing ring" adapter. However the gold cup electrodes furnished by OpenBCI have different dimensions than those of this system. The MKS electrodes mate with their "fixing rings" to hold the electrodes in place.

    The MKS cap system is intended for gel application. This won't last through the night as the gel dries out. Sleep labs use a combination of cup electrodes (with Ten20 paste) and 'colloidion' coating that keeps them moist and not drying.out.


    Or alternately you can see the use of a non-breathable tape shown in these photos,


  • Any more ideas????? @wjcroft and everyone else ;-) 

    Having found out Openbci does not work with bioexplorer / brain-trainer (I wish there was a way). I am looking for a alternative to the electrocap they use which seem expensive and you have to use the gel. 

    Any updates on the dry comb type cheap caps? 

    Should I do a Optima brain Amp with some dry comb like electrodes or the above gold pin comb electrodes in a cap. 

    Any other ideas. Not so keen on Velcro made ones and brainnet looks cheap and has bad reviews for quality.Does caputron have anything that can be made? Aren't those Gamma ones as expensive as the electrocaps?

    Dry Electrode

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