In the study of mechanical networks in control theory, an inerter is a two-terminal device in which the forces applied at the terminals are equal, opposite, and proportional to relative acceleration between the nodes.
He observed that the analogy was incomplete, since it was missing a mechanical device playing the same role as an electrical capacitor.
Shortly after its discovery, the inerter principle was used under the code name of J-damper in the suspension systems of Formula 1 racing cars.
[2][3] J-dampers were at the center of the 2007 Formula One espionage controversy which arose when Phil Mackereth left McLaren for Renault.
Researchers are developing new vibration-control devices based on inerters to build high-rise skyscrapers which can withstand high winds.