Microneedles offer pain-free alternative to hypodermic jabs

Hypodermic needles are widely used to extract blood and inject drugs, but they can be painful, cause scarring, and pose an infection risk. In contrast, microneedles are short, thin and minimally invasive. They also reduce pain and the risk of infection and are easy-to-use.

Project aims to deliver pain-free microneedle contraception

Microneedle contact lens targets the eye for drug delivery

A major drawback is their weak adhesion to tissues for controlled drug delivery, or for biosensing, which involves using a device to detect DNA, enzymes, antibodies and other health indicators.

Now, with 4D printing, engineers at Rutgers University-New Brunswick have created tiny needles that mimic parasites that attach to skin, according to a study in the journal Advanced Functional Materials. While 3D printing builds objects in layers, 4D goes further with smart materials that are programmed to change shape after printing. Time is the fourth dimension that allows materials to morph into new shapes.