An angel investor is an individual or group that can provide $50,000 to $500,000 of capital into your business in exchange for equity such as preferred stock. It is often the first source of financing (other than financing provided by friends or family). They can supply the capital to get the business to a stage where it can qualify for venture capital.
Angel investors are willing to take a high risk in exchange for a high return. Typically their participation will be contingent upon there being a suitable exit strategy. This funding comes at a high price.
You are going to have to sell the viability of your business to the angel investors. You will need a business plan, as well as an elevator statement and executive summary. Have your IP (patents, trademarks) applications on file.
Angel investors can be located through an internet search engine. Another group is the Houston Angel Network.