Esmerelda the robot wheeled around the floor, her arms lifting up and down on hydraulics. She scooped up small red-and-blue cones and stacked them onto rods of varying heights, her motors whirring.

On the edge of the fenced-in floor, Lexington High School student Anna Labbe gave commands: Up, down, turns and navigations. Her teammates, Nora Kapoor and Arushi Aggarwal, used controllers to drive her around.

Esmerelda was designed, programmed and built by members of the Parity Bits, a robotics team for girls and nonbinary students at Lexington High School.

Their name is a pun: A parity bit is a form of error-detecting code, added to the end of a string of binary code. It’s also a reference to gender parity in STEM fields.

Women make up almost 30 percent of the STEM workforce, according to the professional association STEM Women. The Parity Bits want to increase that number.

Esmerelda is about 18 by 18 inches, with purple and gold accents. She weighs about 30 pounds and is made of metal, wood, string and electrical wiring. The Parity Bits take her to competitions, where they and other high school teams see which robot can quickly and most efficiently stack cones.

A small purple and gold robot on a wooden desk.
Esmerelda, the robot built by the Parity Bits.
Karen Marshall GBH News

Their mission also extends to outreach: They visit elementary school students, where they present their robots and teach younger students about engineering.

The Parity Bits were founded in 2014, born out of a co-ed robotics team at their school, 2 Bits and a Byte, when one member wanted a space for girls to shine — without being overshadowed by the boys.

“I started back in fourth grade, but that was because my brother had a team with all of his guy friends,” Defne Olgun said. “And then as I got old enough to join, they were like, Oh, would you like to join us? Because we need girls on our team, so it looks good for the judges. I wasn't always the most confident. I would fiddle around with the Legos, but I wouldn't be the one putting the things onto the robot.”

Most of the team had no robotics experience before joining the Parity Bits. Team member Priyanka Iyer says it's a common experience for girls exploring robotics — and that makes wins even more gratifying.

“I think that when I’m in a community where my voice feels overshadowed by men, I sometimes don't feel confident in what I have to say, and I think their ideas are better,” Iyer said. “But then to be in an all-girls team and show that it is possible and we can do as much as they can. … To be able to do the same thing and go out and win awards and win matches with them, it feels really cool.”

Aggrarwal said they foster an environment for learning, and for feeling secure in being able to practice, fail and try again.

“You're not going to be perfect the first time,” Aggrarwal said. “And that's something that I think is hard for newcomers to remember. Part of that was saying to our new team members, you're going to be okay. And if you're not okay the first time, after the fourth or fifth or sixth time, Esmerelda is going to be fine and we're all going to be fine together.”

Olgun said they also learn how to overcome challenges together.

A teenager holds purple and yellow wheels, smiling at the camera.
Audi Lin of the Parity Bits, a Lexington High School robotics team, holds omnidirectional wheels the team uses for its robot.
Gal Tziperman Lotan GBH News

“Yes, it might suck when the string snaps for the eighth time that day, but you just have to keep going at it again,” Olgun said. “It’s also about sharing space and allowing others to take up as much presence in the room as I might sometimes; to fail on purpose and be okay with that process of growing and learning through the engineering process.”

The environment has inspired many of the girls to pursue careers in science, technology, engineering and math after high school. Two of the graduating seniors plan to study computer science and robotics, and another plans to study mechanical engineering.

They've become close friends along the way, and are leaving a legacy for the underclass girls behind them.

“Over the course of the season, we're all trying to learn and grow as a team,” Audi Lin said. “We want to leave as much as we can behind for future generations.”

At the end of the season, Esmerelda will be disassembled. Her parts will be used for a new robot next year.