A diaphragm is a silicone, cup-like object that you insert into your vagina to cover your cervix. Diaphragms must be used in conjunction with spermicide, which is a sperm-killing gel. A diaphragm ...

Instead of trying to make an air-tight piston, he added a rubber membrane and a clever valve system to create a diaphragm air engine. This GIF is worth 115 words A round rubber diaphragm with a ...