Recent growth in the widespread implementation of piezoresistive materials and their development raises the need for research on their characteristics, especially in the case of biopolymers. This research focuses on the defining of electrical characteristics of a k-carrageenan-based piezoresistive film intended to be used as a transducer in force and pressure sensors. This film was prepared using the natural polysaccharide derived from the Baltic Seaweed Furcellaria lumbricalis; therefore, it is cheap and biodegradable. The main issue is material inhomogeneity due to natural causes, surface microstructure, and various additives, such as Fe2O3, which behave as semiconductors. Characterization of the force-sensitive film was performed using a high-accuracy micropositioning system combined with a resistance measurement device. The obtained results show the distribution of material resistance in the form of a map and support the hypothesis that the real material surface area strongly differs from the geometric one, the film surface is not uniform, and has microcapillaries; therefore, an accurate definition of the film surface charge transfer mechanism and its efficiency require experimental evaluation before implementing such film in practical measurement application.