Alright, first off, we need a power source that’s safe to touch—maybe a small, rechargeable battery pack tucked inside the handle. Then the sensor has to be a low‑power touch sensor that can detect a swipe and translate it into a heat‑or‑cool command. For heating, a Peltier module works but it’s heavy; better to use a tiny induction coil that heats the mug’s inner surface with a controlled current. Cooling could be done with a small thermo‑electric cooler, but the energy cost is huge—so maybe just circulate a chilled liquid around the rim or use phase‑change material that cools when the hand slides off. Next, insulation is key. Wrap the mug in a double‑wall vacuum and a silicone coating that lets the heat go in one direction but stops it from leaking out. Add a smart thermostat inside so the mug never overshoots. Then there’s the UI: a discreet LED strip that glows when heating and flickers when cooling, so you don’t have to look at the mug. Finally, a quick‑release button to lock the temperature in case you’re in a rush. With all that, it’d be a real kitchen staple—just be careful not to get your fingers burnt on the heated side!