A Grade 11 Hoërskool Schweizer-Reneke pupil is hoping to find a way to help amputees to not spend hundreds of thousands of rand on prosthetics. Farida Cajee, 18, from Schweizer-Reneke in the North West has invented a "mind-controlled 3D-printed prosthetic hand" that aims to be a cheaper prosthetic alternative.Speaking to News24 on Thursday, the teen said the idea came when she had to prepare for the 2019 Eskom Expo for young scientists, which she had been taking part in for the last seven years.Because she wanted to win gold, she decided to do something different that would make a difference to society, while also being unique.At the time, her mother was sick and her medical expenses were taking a toll on her family. That was when she, along with her mom, realised that something more biomedical-related would be ideal for the expo. Uses brainwaves"My project started simple because I wanted to prove that it could work, and at first, it didn't. It was such a mission to get the parts, figure out a control unit and to think how it is going to use brainwaves to work and still be cheap," Cajee said.After conducting research for almost three months, she added, she eventually came across an electroencephalograph (EEG) headset that measured brainwaves.Cajee said she used the headset and brainwaves to concentrate and turned it into movement, but that was not enough, she went further and took the PET bottles that were lying around and recycled them to make a prosthetic hand."After the research, I bought myself an Arduino and connected it to the hand, programmed it, coded it and connected it to the headset; and it worked."Cajee said the headset read brainwaves, and when one concentrated, the prosthetic hand opened, and when one relaxed, it closed. 'So many people forced to live without prosthetics'She added the main goal of the project was to lower medical costs. As it stands, her invention costs R9 000 while a regular below elbow prosthetic in South Africa costs anything from R140 000 upwards. "I saw war zone amputees and I figured that these people come back after having served our country and other countries as well, and they are saddled with medical bills because of their injuries. So many people are forced to live without prosthetics because they can't afford it." She said a lot people have been trying to help her produce the prosthetics and to also start a company to produce them.Cajee, who aspires to venture into the medical field once she passes matric, won a gold medal at the Science Expo and was also crowned the best female project.