There are at least a few (new) open source or DIY projects. Future of Sex reported about a Strap-on project named Dildo It Yourself.
They created a website for sharing designs for strap-on dildos. In addition the strap-on dildos is part of a harness. Some parts can be 3d printed but the harness must be made by leather or other material which could be out of scope for most DIY people. The inventors say that their toys are made for ecosexuals which practise sex in nature.
Another project is very impressive as it offers a touch surface for a “insertible toy” eg a penis. This could be used for teledildonics application for capturing and transmitting haptical experience. The construction of the capacitive surface is very impressive. In addition algorithms are introduced for gesture recognition. Gestures? The author explains: “Well, I want to be able to tell what the user is doing with the device (e.g. blowjob, licking, hand job and penetrative buttsex)”.
Another exciting project is a masturbator demonstrator which was molded using 3d printed forms.
Finally there is a very interesting website from the “mad scientist” Franklin. He has made a lot of stuff like a gesture controlled vibrator, a brain controlled vibrator and a Bionic cock.
For commercialisation a Company Tacit pleasure was found. That was back in 2014, but the work is still interesting.
Although these projects are very different in aspects like audience, technical elaborateness and motivation they show the richness of sex tech projects.