Kid of the Year Finalist Lino Marrero, 15, Invented a Shoe That Can Charge a Cell Phone
Lino Marrero, a cello player in the Cello Society of America (CSO), noticed several small blisters on his fingertips as he left practice. Ten-year-old Frisco inventor Lino Marrero, Tx felt so much pain that he had to quit cello practice. He wanted to stop playing his instrument, even though music was important to him. He began to research the internet for a solution. “I learned that a lot of musicians actually quit their instrument because of finger pain,” says Marrero, now 15. “That’s when I realized I need to invent something for this.” A few months later, the “String Ring” was born. It’s an adjustable band that protects a string musician’s sore and blistered fingers so that they can keep practicing without a loss of sound quality.
Marrero’s first invention was a success, but he didn’t stop there. After realizing how costly and harmful having multiple shoes, Marrero created an eco-friendly shoe that could be replaced with soles. “Shoe waste contributes a lot to landfills,” he says, “especially since they have rubber soles that don’t dissolve easily.” Instead of owning separate shoes for different sports—such as soccer cleats or basketball sneakers—Marrero’s invention allows athletes to keep just one pair in their closet.
The self-proclaimed “serial inventor” has a notepad full of inventions like these. An inventor log is kept next to his bed. It contains hundreds of pages full of ideas and mockups. On the very first page is a message he wrote to his future self when he was 10 years old: “This log, in all its staple marks and all its eraser marks, are proof that every time I thought I was done, I had only just begun.” The message, he says, inspires him to keep inventing.
Marrero believes that being an inventor means helping others and creating solutions for everyday problems. “I always start with a problem and how it affects other people,” he says. “Can I bring more music to the world? Do I have the ability to make sports accessible to everyone? Can I help the environment positively?”
He used to disassemble old radios and TV remotes as a kid. “I really like to get inspiration from my everyday life,” he says. He was inspired by everyday challenges and all of his inventions. After he had finished his soccer practice, he tried to phone his mother to inform her that he wanted to invent Kinetic Kickz. But his phone was dead, and he didn’t have a charger. While he was sitting on the soccer field, his mind wandered back to what his teacher told him about renewable energy sources. He could use the soccer-related energy to charge his phone. “I went home and researched all about it,” he says. After hours spent at the drawing table, playing with wires and making 10 prototypes, he developed a shoe insert which captures kinetic energy to be used as a battery for charging a smartphone. Marrero calculated that 12 minutes walking could generate sufficient kinetic energy for a 10 percent charge of a phone’s battery.
Marrero was able to finally test his invention after a severe winter storm brought down power in Texas in the early 2021. However, he realized that the shoe needed some adjustments to be more comfortable. He decided to put the technology in the sole instead of slip-in and make it so that the stored energy can go straight into a USB powerbank so it could be used later.
“No one in my family is an engineer or anything like that,” Marrero says. “So I went to the library, I went online, and I found out about piezoelectric discs and diode bridge rectifiers on my own.”
He hopes that the future will see the use of Kinetic Kickz and its technology in order to generate clean energy, reduce the impact of climate change, and is able to achieve this dream. Although solar and wind power are gaining more popularity, Marrero says he prefers kinetic energy because “you can’t always depend on the wind to blow or the sun to shine.” A high school freshman now, Marrero wants to inspire other children and teenagers to be inventors too.
According to Marrero, younger people have different views that could be helpful in thinking up new ideas. But they also need encouragement. “So much of the world is kids,” Marrero says. “We need to get a chain going, where I inspire someone and they help inspire someone.”