A SAW device has a substrate configured to propagate acoustic waves; an IDT electrode on a first main surface of a substrate ; and an electrode pad on the first main surface electrically connected to the IDT electrode. The proteins are useful for vaccines, immunogenic compositions, diagnostics, enzymatic studies and also as targets for antibiotics. The back of the patch has a weak adhesive which is gentle to the skin. The transmit buffer provides an asynchronous interface between a transmit source and the serializer.