Printed medical coatings

Figure 2: Drop generation and impact during inkjet dispensing process are influenced by material properties and other effects

Continuing miniaturisation of many products requires a method of dispensing very small amounts of liquids. Inkjet technology is capable of applying adhesives and many other functional liquids as well as inks with great precision. Its versatility and potential in industrial applications is illustrated by the example of coating a drug-eluting stent with a polymer/drug formulation. In many production processes it is necessary to dispense small amounts of fluids. There are many possible examples: placement of adhesives to bond devices such as optical lenses or fibres, printing of functional materials onto computer displays or sensors and dosing of lubricants as well as the application of coating materials. A consequence of continuing miniaturisation is that the amounts of fluids also need to be "miniaturised". Conventional methods for dispensing and dosing are at their limits. The volumes achievable are too large for applications in the millimetre and sub-millimetre range. Wilhelm Meyer reports in the February issue of ECJ how precision coating of medical devices can be achieved by printing.