As he scoured Europe to find parts last year, German entrepreneur Florian Simmendinger was able only to locate a handful of motors small enough for the wearable, smartphone-controlled metronome he was building to help musicians keep the beat — and even they were too weak.

But a move to Hong Kong in November jump-started the development of his product, as he was soon able to find everything he needed in the sprawling Chinese manufacturing hub of Shenzhen, just across the border.

“In Shenzhen, they sell every motor that has ever gone into a consumer product and I was able to get the one I needed, which is 600 per cent stronger than a mobile phone,” he says as he shows off his $99 Soundbrenner Pulse, which looks like a watch and emits vibrations rather than an intrusive tick-tock sound.