Abstract: The present invention concerns a new process for depositing a thick compact layer of biomolecules for instance such a layer with thickness in the ?m scale and, for depositing a thick compact layer of cells in the ?m scale. The deposited layer is made by application of an unbalanced (asymmetrical) alternating voltage polarization between two electrodes to a dissolved biomolecule or cell from low conductivity solutions. The process allows the rapid manufacturing of sensors and the coating of devices with functional cells and biomolecules. Examples are provided on the preparation of functional sensors such as a glucose, a lactose sensor, a hydrogen peroxide sensor and a glutamate sensor. Examples are also provided on the deposition of eukaryoric cells such as saccharomyces cerevisiae. The examples demonstrate a process that can be applied to coat devices with biomolecules and biological cells.