Activities are concentrated around the concept of what we are calling mechanical meta-materials. We use this term to refer to systems that consist of more than one mechanical oscillator or electro-/opto-mechanical unit, interacting together. Prospective applications of such devices include devices that transmit light or microwave radiation only in one direction, as well as synchronised networks of many mechanical oscillators to produce low phase-noise signals. The HOT researchers have made several advances over the past twelve months. In a set of three papers published in top-ranking journals, EPFL and the University of Cambridge demonstrated a device that transmits electromagnetic radiation preferentially in one direction, with the capability to change the preferred direction at will, and showed how to build a directional amplifier in a similar manner; the University of Malta and IST Austria then discussed how this idea can be used to control the direction of flow of heat in nanoscale devices. Three other prestigious publications by the University of Malta and the Max Planck Institute for the Science of Light showed how mechanical meta-materials can be used to impose artificial magnetic fields for light and sound, and how to create topological insulators for sound waves, which may have applications to signal processing using sound. One key issue with our devices is the simplification of read-out and control protocols. The University of Malta and the Max Planck Institute for the Science of Light discussed how taking a “bird’s eye view” can help simplify the analysis of such systems. The University of Camerino published two studies that illustrate how to use feedback to enhance the optomechanical interaction. Tackling the issue of controlling increasingly complex mechanical systems, the University of Constance published work detailing how to couple to and control mechanical systems with multiple oscillation modes.