Needle-free injection technology is becoming increasingly popular, and there are several devices that use different methods to deliver vaccines and medications without needles. Devices Using Various Technologies : - PharmaJet's Needle-free Injection Systems: These devices use a spring-powered mechanism to create a high-pressure stream of fluid that penetrates the skin. Examples include the Tropis Intradermal System and the Stratis Intramuscular or Subcutaneous System. Needle-