Mayim Bialik opens up on "The Big Bang Theory," girls in STEM

Mayim Bialik wears many hats: She's an actress, a cookbook writer and a scientist, but Bialik says her favorite role is "mom" to her two sons.

Bialik is known to most, though, as Dr. Amy Farrah Fowler on "The Big Bang Theory," and she says she has enjoyed watching her character grow on the hit show, which returns to CBS on Sept. 21.

"She's evolved a lot," Bialik tells CBS News. "She went from being very insecure, socially, to much more confident ... With Sheldon (played by Jim Parsons), she's gotten a lot more clear in her communication, which has led to some conflict, but we see her more comfortable socially in a way that Sheldon doesn't -- he's comfortable where he is, but Amy really wanted to evolve."

As for season 8's cliffhanger that left viewers wondering if Amy and Sheldon will stay together? Bialik says she doesn't know what will happen, and she prefers it that way.

"I only know the three episodes we've done so far," she says. "I don't like to know -- I just like to take it week to week. I think the beginning of season 9 will be exactly where they left off and deal directly with what happened, but nothing's going to get resolved quickly."

She's not worried about what that means for the future of the show.

"All these characters work together, even if they're dating, not dating, in a fight -- it kind of works together because this is their social group, whether they're in committed relationships or just figuring it out," she says.

And Bialik says it's not just the characters who work together -- she says all of the people on set make a great team in real life.

"I spend more time with them than I do with my family," she explains. "You grow into a family and we do enjoy each other. It's a nice place to work -- our writers, our great, wonderful crew -- we have a good situation and I'm grateful for that."

Even though most of her life is on set, the former "Blossom" star makes time to spend on issues she finds important, like getting girls to feel confident when studying STEM subjects. Bialik is teaming up with Texas Instruments to make STEM subjects (science, technology, engineering and mathematics) "cool." She says she was lucky to have a strong female mentor when she was young.

"I feel that a lot of that is having other women I could look up to to help navigate through most of the bias had when I was younger, thinking science wasn't for me," she explains. "It took having a female mentor to help me understand I was capable and competent enough to be a scientist, and that's what I hope to do with Texas Instruments."

Bialik, who is running the #ilyTIcontest campaign with Texas Instruments to have kids why they love their technology, says she wants to young women to have the right impression of what it means to be in STEM fields.

"I want to show people what it feels like and looks like to be a scientist, and part of that is to get technology scientists use into young hands as soon as possible," she says. "Having female role models is important, and so is talking to young girls and having mentorship opportunities so they can feel what it's like to actually be a scientist, rather than feeling that they'll just be alone in a lab one day."

Bialik has shown young girls that scientists can also act on TV and whip up a mean vegan chickpea burger.