How does one-way bulletproof glass work?
One-way bulletproof glass is composed of two layers. The outside layer – on the threat side – is made of a brittle glass and the inside layer is a flexible polycarbonate. A bullet that strikes the brittle external layer first causes the glass to break inward toward the polycarbonate layer. The glass breaking absorbs some of the bullet’s energy by spreading the force over a larger area and the flexible polycarbonate stops the bullet. Bullets shot from the inside of an armored car are able to penetrate the bulletproof glass because they strike the polycarbonate layer first with more focused energy. The brittle glass layer then breaks outward allowing the bullet to pass through with minor energy loss.
