76 TIME February 28/March 7, 2022
LINO MARRERO WAS LEAVING CELLO PRACTICE
one day when he noticed several blisters on his fi n-
gers. The pain was so bad that the then 10-year-old
from Frisco, Texas, wanted to quit playing for good,
even though he loved music. So he started doing
some research online to fi nd a solution. “I learned
that a lot of musicians actually quit their instru-
ment because of fi nger 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 string
musicians’ sore and blistered fi ngers so that they
can keep practicing without a loss of sound quality.A year later, at age 11, he created an eco-friendly
shoe with replaceable soles. “Shoe waste contrib-
utes a lot to landfi lls,” he says, “especially since
they have rubber soles that don’t dissolve easily.”
The self-proclaimed “serial inventor” keeps a
log next to his bed, with hundreds of pages of ideas
and mockups. For Marrero, being an inventor is
about social change and creating solutions to every-
day challenges. “I always start with a problem and
how it aff ects other people,” he says. “Can I bring
more music to the world? Can I make sports more
accessible for everyone? Can I help the environ-
ment positively?”
He came up with the idea for his latest inven-
tion, Kinetic Kickz, after he fi nished soccer prac-
tice and tried to call his mom to let her know he
was ready to be picked up. But his phone was dead,
and he didn’t have a charger. As he sat on the soccer
fi eld, he thought back to what his teacher had said
about renewable-energy sources. What if he could
harness the energy he expended playing soccer to
power his phone? After spending hours tinkering
with wires and creating 10 diff erent prototypes,
he fashioned a shoe insert that collects kinetic en-
ergy and converts it into battery power. Marrero
calculates that 12 minutes of walking can gener-
ate enough kinetic energy to charge 10% of a cell-
phone battery.
When a freak winter storm in Texas caused
massive power outages in early 2021, Marrero got
to test his invention during a time of need, and it
worked. But he also realized he needed to make a
few adjustments: now the collected energy goes
straight to a USB power bank so it can 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
disks and diode bridge rectifi ers on my own.”
His dream is that the technology in Kinetic Kickz
could be used to create clean energy and limit the
eff ects of climate change. 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.”
Now, Marrero wants to push other kids to be
inventors and solve global problems. “So much
of the world is kids,” he says. “We need to get a
chain going, where I inspire someone and they in-
spire someone.” —NIK POPLILino MarreroInventorFRISCO, TEXAS / 15
Marrero honed his
power-generating
shoe design during
the Texas freeze of
February 2021Jenell Theobald, 15
Theobald created Let’s Peer
Up, an organization that
advocates for representation
for those with mental and
physical disabilities.BEAVERTON, ORE.
Ruby Kate Chitsey, 14
Chitsey founded Three Wishes for
Ruby’s Residents, a nonprofi t
organization that works with nursing-
home staff across America to fulfi ll
small wishes for seniors.HARRISON, ALASKA
Khloe Joiner, 9
Joiner founded
A Book and a Smile
with a mission to
donate 1 million
books to children.