I saw a prototype of a new type of single-thread chainstitch sewing machine. It has a swiveling part that twists the loop before the hook catches it, supposedly making it as resistant to unraveling as a standard lockstitch. There are probably good reasons why the inventor still hasn't attracted capital (or maybe shady anti-competitive ones?), but I'd still love to play with the prototype

edit: my bad it's actually a two-thread chainstitch