Tapered microstructure for impedance matching using PDMS moulding

The object of this work is to consider the feasibility of making a tapered acoustic matching material using microfabrication techniques. Linearly tapered microstructures having a base width of 5-10 μm and height of 20-50 μm were fabricated by using double sided, dual angle lithographic methods to form an SU8 mould. Into this Polydimethylsiloxane (PDMS) is cast which is then electroplated. This method of construction is compared with our earlier work and it was found that it simplifies electroplating and greatly reduces costs. In addition, with this method fluid-metal taper sections are possible.