Chair felt pads that stay on
I recently gave up on the felt pads when I saw an odd alternative on Amazon:

NancyProtectz Ribbed Furniture Sock



These may not be the least obtrusive furniture feet and might not lend to the modern look or feel of the Ikea chairs, but I've been using them on square, wooden furniture legs for a few months and they do fairly well sliding across 100-year old hardwood floors. None of them have fallen off yet, but they do occasionally need to be "hiked-up".