Undergraduate students of the prestigious Massachusetts Institute of Technology have developed a shock absorber that harnesses energy from small bumps in the road to generate electricity.

Not only does it smooth the way, it could also soon generate electricity for the drive: the shock absorber. The basic purpose of shock absorbers is to manage the movement of the spring and suspension by converting the kinetic energy produced by the suspension to thermal or heat energy degenerated by means of hydraulic fluid.

Students at MIT who were looking at where energy is wasted in vehicles, saw the potential in harnessing this so far unused vented energy. They developed a generative shock absorber, which could be used to recharge batteries just like the energy from regenerative breaking in EVs and HEVs, and according to team member Shakeel Avadhany, can achieve up to 10% improvement in a general vehicle’s fuel efficiency.

A variety of car models was tested by outfitting the suspension with sensors and feeding the data into a computer. These tests showed that a significant amount of energy was being wasted in conventional suspension systems, especially in heavy vehicles. To make this energy usable, the students built prototype shock absorbers that use a hydraulic system, forcing fluid through a turbine attached to a generator. The system is controlled by an active electronic system that optimises the damping, providing a smoother ride than conventional shocks while generating electricity to recharge the batteries or operate electrical equipment.

In their testing so far, the students found that in a 6-shock heavy truck, each shock absorber could generate up to an average of 1 kW on a standard road - enough power to replace the large alternator load in heavy trucks and military vehicles, and in some cases even run accessory devices such as hybrid trailer refrigeration units.

The U.S. army and several truck manufacturers have already shown interest, AM General (who produces military, all-purpose vehicles such as the Humvee) have even lent the students a model for testing purposes.

The team has received help from MIT's Venture Mentoring Service, and has been advised by Yet-Ming Chiang, the Kyocera Professor of Ceramics in the Department of Materials Science and Engineering and founder of A123 Systems, a supplier of high-power lithium-ion batteries.

The students filed for a patent last year and founded the company Levant Power Corp. to develop and commercialise the product. They plan on having a final, fine-tuned version of the device ready this summer. Then they will start talking to potential big customers. For example, they have calculated that a company such as Wal-Mart could save $13 million a year in fuel costs by converting its fleet of trucks.