Portable Ceramic Burr Coffee Grinder works off Rechargeable Battery with USB Charging
I always carry a manual mini grinder when I go to work, to freshly grind the coffee beans before I make coffee but the handle is starting to wear a bit and I tend to get distracted at my desk so a grind can sometimes take 30 mins or more.
I've discovered these interesting models (yes there are various ones and also available off Ali Express) that are charged via USB and will grind the beans using an electric motor. They seem to have ceramic burrs and the only caution is not top lose the USB cable as it recesses more deeply than standard cables do. It looks like it should fit in the handle of my Aeropress coffee maker too.