Coulomb-blockade results are recorded at room temperature and normal pressure in monolithically integrated structures using GaAs wedges with a radius of ~25nm and a minimal gap to the anode when a quasi-vacuum can be assumed. These devices have very low capacitances being of order 10^-18F. A concept is presented where this Coulomb blockade is used for signal production and storage in an ultra-dense memory-matrix application. A one-dimensional high-electron mobility heterostructure together with local resonant interband tunnelling, isolated by deep ion implantation are proposed for the buried layer access electronics.