I have experience manufacturing in China and the robots at Wonder Workshop (Play-i) are made in China in reasonable quantities. Quality control is the big issue with outsourcing to China. The only way to ensure the quality is what you want is to oversee the manufacturing yourself or pay one of the few good QA consulting groups to do it for you. I'm pretty picky so I like to oversee it.
Making in the US is a great luxury if you can afford it - that is, will your customer pay enough to allow it. Typically in the US you need automation or some other advantage to make manufacturing competitive with outsourcing. It's impossible to gauge if 6 pieces per day is a good or scalable number without knowing the complexity and cost of the product.
The biggest challenge to outsourcing is the MOQ (minimum order quantity). If you don't have a sufficient order for the typical manufacturer of the type of product you are making, then they won't be interested in the business. This is assuming you can find a manufacturer who your are confident can do the work at the quality level you require. This is typically not a trivial problem.
I guarantee that there are manufacturers who can do silicon at a quality you would be impressed with. So it's just a matter of finding them, meeting their MOQ then verifying the production is up to standard.
I hope this is helpful.