Opt to Publish Your Work as Open Access
The IOS Press Open Library offers authors an open access (OA) option. By selecting the OA option, the article will be freely available from the moment it is published, also in the pre-press module. If you choose this option, the article processing charges are paid in the form of an open access fee. Authors will receive an open access order form upon acceptance of their article. Open access is entirely optional.
See the IOS Press Open Library policy for more information about this option, and also to check if there are any institutional agreements that you might be eligible for.