Inspired by nature, molecular communication uses molecules or other information particles in the nanoscale to establish a communication link. By engineering such a data transmission it is possible to overcome some limitations of conventional electromagnetic communication methods. especially for transmission challenges in a medical context. Although the concept of engineered molecular communication was proposed over a decade ago, practical realisations in experimental setup have been scarce until recent years. In this work, two testbeds for molecular communication, one using magnetic nanoparticles for a macroscopic transmission distance, and one implemented as a portable lab-on-a-chip system in the microfluidic domain, are presented. Transmitter and receiver systems were developed for both testbeds and evaluated regarding their performance in a communication scenario. The macroscopic testbed is the first fundamentally biocompatible molecular communication setup to achieve a significantly high data rate. With various optimisations and the use of time-based encoding the transmission efficiency could also be remarkably improved in comparison to previous work. The developed compact transmitter and receiver devices are an order of magnitude smaller than in the original proof-of-concept. The microfluidic testbed is constructed as a fully integrated pocket-sized lab-on-a-chip system, that does not require any lab equipment for operation. With the use of coloured ink in a proof-of-concept application, data transmission using molecular-shift keying was achieved.