Patent ID: 8769947

Claim:
An exhaust system configured for converting thermal energy to mechanical energy, the exhaust system comprising: a source of thermal energy provided by a temperature difference between an exhaust gas having a first temperature and a heat sink having a second temperature that is lower than said first temperature; a conduit configured for conveying said exhaust gas; a heat engine disposed in thermal relationship with said conduit and configured for converting thermal energy to mechanical energy, wherein said heat engine includes a first element formed from a first shape memory alloy having a crystallographic phase changeable between austenite and martensite at a first transformation temperature in response to said temperature difference between said exhaust gas and said heat sink; and a member formed from a conductive material and disposed in contact with said conduit so that said member abuts said conduit and transfers thermal energy from said conduit to said first element via conduction; wherein said member includes a plurality of bristles each extending from and flexible with respect to said member and disposed in contact with said first element.