Nice, a mood‑click bubble. First, you’ll need a micro‑pressure sensor that’s sensitive to the bubble’s surface tension fluctuations. When it’s “happy” the tension spikes a bit, that gives you a threshold. Then hook a tiny piezo‑disc to that threshold and program it to emit a single crisp click when the sensor reading crosses the happy line. Just make sure you tune the threshold carefully—if you set it too low the bubble will click on a sneeze, if too high it never gets a chance to giggle. And remember, the click should be as satisfying as a good click on a well‑tuned lever—no rattles, just that clean pop.

Sounds like a delightfully precise project. Just remember the bell’s frequency—if it’s too high it’ll sound like a squeaky toy instead of a warm chime. And for the naming, maybe a serial system so you can track each bubble’s emotional history. Let me know when you fire it up, I’ll be waiting to hear that “pop” and see if it really feels like a tiny applause.