Culture shock

A new shock absorber harnesses energy from small bumps in the road, generating electricity while it smoothes the ride more effectively than conventional shocks.

The team of MIT undergraduate students that invented the device hope to initially find customers among companies that operate large fleets of heavy vehicles. They have already drawn interest from the US military and several truck manufacturers.

Shakeel Avadhany and his team-mates said that they could produce up to a 10 per cent improvement in overall vehicle fuel efficiency by using the regenerative shock absorbers.

The company that produces Humvees for the army - and is currently working on development of the next-generation version of the all-purpose vehicle - was interested enough to loan them a vehicle for testing purposes.

'We wanted to figure out where energy is being wasted in a vehicle,' said team member Zack Anderson. Some hybrid cars already do a good job of recovering the energy from braking, so the team looked elsewhere and quickly homed in on the suspension.

They began by renting a variety of different car models, outfitting the suspension with sensors to determine the energy potential, and driving around with a laptop computer recording the sensor data. Their tests showed that 'a significant amount of energy' was being wasted in conventional suspension systems, especially for heavy vehicles.

Once they realised the possibilities, the students set about building a prototype system to harness the wasted power. Their prototype shock absorbers use a hydraulic system that forces 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 six-shock heavy truck, each shock absorber could generate up to an average of 1kW on a standard road - enough power to completely displace the large alternator load in heavy trucks and military vehicles and, in some cases, even run accessory devices such as hybrid trailer refrigeration units.

They filed for a patent last year and formed a company, called Levant Power, to develop and commercialise the product. They are currently doing a series of tests with a converted Humvee to optimise the system's efficiency. They hope that their technology will help give an edge to the military vehicle company in securing the expected $40bn (£27bn) contract for the new army vehicle, called the Joint Light Tactical Vehicle (JLTV).

The new shocks also have a fail-safe feature: if the electronics fail for any reason, the system simply acts like a regular shock absorber.

The group, which also includes Zachary Jackowski, Paul Abel, Ryan Bavetta and Vladimir Tarasov, plans to have a final, fine-tuned version of the device ready this summer.