I don't know if a product I designed can have a market.

I'm not sure, but you have to have connections to get into school. Now many schools use whiteboard pens or oily pens. In fact, schools are also saving teaching costs. This can only be popularized except for teachers engaged in scientific research. If you are a student or have a whim, you are an investor or have nothing to do. You can't develop this market, the market cost is very expensive.