Biological membrane nanopores have brought about a step-change in portable, scalable DNA sequencing and helped tackle the Covid pandemic. Nanopores are also used as research tools for label-free and fast single-molecule analysis. Yet, the barrel-like biological membrane pores of a few nm width cover only a tiny space in the possible size and shape spectrum and therefore miss out on many applications. In my talk, I show how rational design with DNA can drastically expand the structural and functional range of membrane pores. The design strategy forms tuneable pore shapes and lumen widths of up to tens of nanometres with the option to attach functional units for bimolecular recognition. The designer pores may be applied for portable and scalable sensing in diagnostics, environmental screening, or homeland security. The pores also illustrate how DNA nanotechnology can deliver functional biomolecular structures for synthetic biology.