The idea is great in principle. But this is going to be a problem:

"We need a mechanical device which can automatically sort the samples into well group"

PCR machines are actually not that complicated by comparison. Basically just a programmable heater.

Last time I looked into it (admittedly a while ago, so feel free to correct me), pipetting robots kind of sucked and weren't very precise.

Correctly handling tiny (microliter scale) fluid amounts without the slightest risk of cross contamination isn't going to be that simple.

But all that said, if you can solve this problem I think the idea is a real winner. Can be used for HIV and other PCR based testing as well.