Microneedles have now been produced from ceramics, metals and polymers. The general properties of ceramics suggest the needles would be resistant to compression but fragile under shear forces. Polymers have a low Young's modulus, therefore, could deform before puncturing the skin. Metals have been used in hypodermic needles for a long time. They are strong enough to break the skin barrier but mass producing micro components from metal is often very expensive, therefore, using conventional manufacturing methods, it might not be the best material of choice for a product that requires to be made in the billions annually. For metals to be considered as a viable material for microneedles, it is necessary to propose a new manufacturing method that is suitable for low value high volume produced micro component. -- Ultrafine-grain Al1050 has been created using Incremental equal channel angular pressing. The finer grain structure should allow for smaller detail to be produced as well as being stronger. Experimentally it has been shown that allying ultrasonic to the backward extrusion process can reduce the forming force by about 20 percent while increasing the height of the microneedles by 80 percent. Using UFG material results in greater needle height uniformity across the billet. It was also found that applying gold to the surface of the billet improves the formability of the needles.
| Date of Award | 7 Mar 2019 |
|---|
| Original language | English |
|---|
| Awarding Institution | - University Of Strathclyde
|
|---|
| Sponsors | EPSRC (Engineering and Physical Sciences Research Council) |
|---|
| Supervisor | Andrzej Rosochowski (Supervisor) & Richard Anthony Black (Supervisor) |
|---|