Magnetic nanoparticles (MNPs) based additively manufactured memory devices

Magnetic nanoparticles (MNPs) in a suspension have been shown to change resistance by an order of magnitude based on an applied field. We have prepared the MNPs samples with matrices of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PDOT:PSS) or H₂O, and Co MNPs and carried out the magnetoresistive measurements. A switch-based model is used to understand the mechanism for the change in resistance. We further propose devices for memory based on MNPs. Building blocks for these devices are then fabricated using additive manufacturing techniques and measurements of change in resistance under the influence of a magnetic field are conducted. Niche applications of additive manufacturing techniques to the fabrication of these devices are proposed. The device uses MNPs suspended in a soft matter matrix. The application of a magnetic field is used to move the MNPs to or away from electrical contacts. Depending on the change of position of the MNPs, a connection is either made or broken, which can act as a 1 or a 0. The measured change in resistance observed in such devices is more than an order of magnitude depending on the matrix solution. The proposed device and its manufacturing process could be feasible for magnetic memory and in-memory computing devices on any flexible substrates.