Sharing Confidential Prototype Information?

Blockshrimp asks: "I have had an idea for creating a hardware device and developing a business based around that hardware. I have been kicking the idea round for about 5 years while I've tried to kick holes in the concept and I think that it should be a disruptive technology for at least another 5 years. I once approached a venture capital group where apart from their lack of understanding of the technology liked the idea and the market enough to suggest that if a prototype was successful they would be interested in the idea. My main problem is that I have two small children and the concept is very risky (from my perspective) to invest the amount of money to create a prototype (~$40000 Australian, $20000 US). How do I share this information with a group of interested people with letting some amoral person/company with available finances from taking the idea and running? "

"My other problem is that my main training is in IT and physics and I'm pushing my basic electronics into places that it probably shouldn't be going. I currently work for a reasonably large research organisation (~7000 souls) doing system administration however the area I'm in caters primarily in the biological sciences. The idea is simple enough so that the benefits of approaching them are outweighed by the disadvantages due to their size, loss of control and so on.

ps. I was once described to someone by a physics teacher as the most gifted student he had taught in over 30 years so there may be some merit in the idea."