During the path of technology development, PI Energy has taken thousands of measurements of the materials, across more than 2,000 prototypes. Some of the images below are small-scale and others are larger scale. Parents love to show pictures of their children, and these pictures below show the progression of PI Energy solar materials evolution from baby-steps to adolescence. The first two pictures are P1 prototype under an electrical test probe. The next couple are iterations of P2. The circular devices with grids are tests of P3 and the last picture is an early picture of testing material processing techniques for the latest generation, P4.