1. Add potassium tartrate and sodium carbonate to a beaker with water. 2. turn on the heater until the solution becomes clear. 3. remove the impurities in the clear solution using filter paper and pour the filtered solution into a container and wait for it to crystallize. 4. Strike the crystallized piezoelectric element and see if it generates electricity. 5. Assemble the piezoelectric element onto a piezoelectric plate. 6. Try tapping the piezoelectric plate with a hammer or hitting it with a ball to turn on the lantern and charge the battery.