3 DIY INVENTIONS 

Both of the electrical ones would work as they are simple circuits, but don't make fire starters out of wood! Also, don't use lithium cells for circuits like this, just use simple cells you can buy in a store. And maybe do some basic ohms law and power calculations.

Hey thanks for the advice, yeah I figured out using wood was a stupid idea and surely will do some few current voltage and power calculations. But about the batteries, is it because they get short circuited and its not good for the cells

​@@TRONLAB7there's certainly risks of fire and explosion when short circuiting a lithium cell, but also there's no charging circuitry there. You would be better off with a couple of AA cells, or off you need higher voltage, a 9v battery. Much less risk with shorting them and you can get rechargeable versions that don't need special charging circuitry to keep safe. If you are going to use lithium cells like that, make sure they include protection circuitry.