A differently complex and smaller approach might be to combine the knob with with an axial flux PCB-BLDC, like what Carl Bugeja made [0, 1]. It might be suited

A differently complex and smaller approach might be to combine the knob with with an axial flux PCB-BLDC, like what Carl Bugeja made [0, 1]. It might be suited to get haptics in something as small as the article's knob, although to get an in-built display you'd have to use one of those displays that fit in lego bricks [2, 3] with a slip-ring. 0. https://microbots.io/products/motorcell https://microbots.io/products/motorcell 1. https://www.youtube.com/watch?v=CVszJMlvZcA https://www.youtube.com/watch?v=CVszJMlvZcA 2. https://github.com/AncientJames/uGrey https://github.com/AncientJames/uGrey 3. https://www.youtube.com/watch?v=0pUV_3qeHog https://www.youtube.com/watch?v=0pUV_3qeHog