How much of a share should I have in a startup based on my PhD research?
TL,DR: You deserve a large majority. I consider 90% for you and 10% for your professor fair.
I finished my Ph.D. and co-founded a company based on dissertation work. I continue to work as a funded tech entrepreneur. I offer the following insights:
From your situation, it sounds like no one else is remotely close to your level of contribution. If you leave, there is no business.
Equity should be determined based on real contribution to the enterprise. You aren't being cruel or disrespectful by placing a value on what people bring to the table. At this point of the business, value equals cash or know-how. Do not award equity to someone who's really eager and ready to "work like a dog" (chances are they will fade in six months) without tying their effort to a vesting period -- they don't receive their equity until after a period of satisfactory work, quantified and agreed-to in writing.
As co-author of the patents, your professor is entitled to proceeds from the use of the intellectual property, but not equity. In this case, you are choosing to give equity in exchange for permission to use the patent. Your business operating agreement should state that.
You need to check the university guidelines regarding use of the patent. Most likely, the patent is controlled by the university and you'll have to work out a licensing agreement.
When all is said and done, you need to have enough cushion to absorb dilution (if you bring on investors or high-level staff), yet retain control or a profitable equity position. I think a 90%-10% split between you and your professor is about right at this point. If you bring on the business student (they may be a nice person, but aren't providing a lot of value), I propose a 85%-10%-5% split with a vesting period for the student. Consider awarding more equity to the student later if they work hard.
Good luck and remember: you have the know-how if people decide to make things difficult. Walk away if needed.
Anything less than giving yourself 100% comes with risks, risks you are probably completely unaware of and with huge complications. What if someone wants to buy the company but only the entire company, but the minority shareholders don't agree to the sale? What if one of the minority shareholders dies, gets divorced, gets sued, etc. and now you have to deal with a shareholder of substantial percentage you may or may not get along with? Are you sure you won't be sued for minority shareholder abuse if you make unpopular decisions?
If you value the success of the endeavor, do not give away shares in it for work that was done for fair wages at the time.
Only give shares out when there is an event that merits another change in ownership such as when someone does offer you funding or at the time of a sale.
Talk to an attorney who is an expert in this specific subject before offering anyone anything.