Having the correct writing posture is extremely important. We have conducted a survey, discovering that only 12% of the participants hold pens correctly, reflecting the urgent need to educate the public on how to hold pens properly. Inspired by the severe impacts of writing with the incorrect amount of strength and in the wrong position, we invented GRIPtech, aiming to help users to improve their bad posture. Our invention uses algae as the power source, which is a new type of biotechnology. According to research conducted by Stanford and Cambridge University, algae can release delocalised electrons during the process of photosynthesis, completing an electric circuit with metal slices, becoming a source of energy. Pressure sensors are positioned at where the thumb, index finger, and middle finger should be placed on the pen grip, detecting the strength that the user utilizes, transferred into the Micro:bit and our app. Each finger has a different range of numbers representing the strength used. If the force used is in the range, the LEDs in the green box would turn off, vice versa. By turning all the lights off, users can hold pens with the correct amount of strength and in the right position.