Molecular communication uses molecules (i.e., chemical signals) as an information carrier and allows biological and artificially-created nano- or cell-scale devices to communicate over a short distance. It is a new communication paradigm and is different from the existing communication paradigm that uses electromagnetic waves (i.e., electronic and optical signals) as an information carrier. Key research challenges in molecular communication include design of a sender, design of a propagation system, design of a receiver, design of a communication interface, and mathematical modeling of the molecular communication components and system. This paper describes the design and the initial experimental results of a communication interface, a propagation system, and a receiver in molecular communication.