It's not all about the money.

According to a new survey of angel investors by Propel(x), some investors aren't just looking at return on investment when reviewing science and technology startups.

Just half of respondents surveyed said the potential for investment returns was their top motivator for investing, while nearly one third ranked solving the world's biggest challenges as top motivation.

Why? It's personal. "Angel investors are investing personal wealth and many want to leave a legacy by helping solve some of the world's biggest challenges through science and technology," Swati Chaturvedi, Propel(x) CEO told CNBC.

"When raising capital, founders should emphasize the impact of their solution besides potential returns to investors," she added. "It's not only about the 'what,' it's also about the 'so what?' "

The study also found that investors want to know the team beyond its founder to get a sense of the brains behind the business.

The study, which was done in collaboration with Breakout Labs, MIT Alumni Angels of Northern California and Innovation Node – Los Angeles, highlighted the importance of keeping technical terms, simple.

Nearly 70% of respondents have invested in science and technology startups, and half of respondents said they would sometimes or often turn down a startup because they didn't understand the technology.

Finally, the majority of investors agreed that having a subject-matter expert will help when evaluating a startup's potential.

"Angel investors are at the vanguard of funding true innovation," Chaturvedi said. "They are swooping in and living up to their names."