A piston capable of reducing undesirable “knock,” reducing hydrocarbon emissions, and providing more complete combustion, is provided. The piston includes a multilayer coating having a thickness of 500 microns or less disposed on an upper combustion surface. The coating includes a bond layer including nickel disposed on the upper combustion surface. A thermal barrier layer including a ceramic composition is disposed on the bond layer. A sealant layer formed of metal is disposed on the thermal barrier layer. A catalytic layer including at least one of platinum, ruthenium, rhodium, palladium, osmium, and iridium is disposed on the sealant layer. The catalytic layer can be disposed on select regions or the entire upper combustion surface to promote combustion through a catalyzed reaction.

A piston having a piston crown with a combustion chamber, and a circumferential ring belt extending from the piston crown and having a plurality of ring grooves separated by piston lands. At least one of the piston lands, ring grooves or top surface of the crown is provided with a coating comprising hexagonal boron nitride. The coating can be made solely of hexagonal boron nitride, or can additionally include a resin. The coating can be a single layer coating or a multiple layer coating.

A piston of a cylinder of an internal combustion engine includes: an upper piston crown; a radially outer surface; a plurality grooves arranged on the radially outer surface; and a plurality of piston rings each positioned in a respective one of the grooves. The radially outer surface forms a top land arranged between the upper piston crown and an uppermost one of the grooves of the piston, and the top land has an axial length and a non-abrasion-proof coating.

A piston of a cylinder of an internal combustion engine includes: an upper piston crown; a radially outer surface; a plurality grooves arranged on the radially outer surface; and a plurality of piston rings each positioned in a respective one of the grooves. The radially outer surface forms a top land arranged between the upper piston crown and an uppermost one of the grooves of the piston, and the top land has an axial length and a non-abrasion-proof coating.

A sensor device system for detection of a liquid adjacent to the sensor having a glass fiber laminate substrate, at least one pair of comb electrodes formed on the glass fiber laminate substrate, a first of the pair of comb electrodes being interdigitated with a second of the pair of comb electrodes, the pair of comb electrodes defining geometric parameters; and a passivation coating covering the pair of comb electrodes.

A sensor device system for detection of a liquid adjacent to the sensor having a glass fiber laminate substrate, at least one pair of comb electrodes formed on the glass fiber laminate substrate, a first of the pair of comb electrodes being interdigitated with a second of the pair of comb electrodes, the pair of comb electrodes defining geometric parameters; and a passivation coating covering the pair of comb electrodes.

A piston for an internal combustion engine is provided. The piston includes a coating applied to a ferrous body portion to reduce or prevent chemical bonding of carbon deposits or coking on the body portion at temperatures ranging from 200 to 400° C. The coating includes a fluoropolymer, such as polytetrafluoroethylene, fluorosilane, fluorocarbon, fluoroplastic resin, and/or perfluoroplastic, and may be hydrocarbon or silicone based. The coating also has a thickness of 25 microns to 1 millimeter. The coating can be disposed on an undercrown surface, ring grooves, ring lands, pin bosses, and/or skirt sections of the body portion.

A piston for an internal combustion engine is provided. The piston includes a coating applied to a ferrous body portion to reduce or prevent chemical bonding of carbon deposits or coking on the body portion at temperatures ranging from 200 to 400° C. The coating includes a fluoropolymer, such as polytetrafluoroethylene, fluorosilane, fluorocarbon, fluoroplastic resin, and/or perfluoroplastic, and may be hydrocarbon or silicone based. The coating also has a thickness of 25 microns to 1 millimeter. The coating can be disposed on an undercrown surface, ring grooves, ring lands, pin bosses, and/or skirt sections of the body portion.

A steel piston with an engineered coating is provided. A high thermal conductivity material, for example copper, is disposed on first regions of a combustion bowl to reduce hot spots in the piston. A low thermal conductivity material, for example a ceramic, is disposed on second regions of the combustion bowl to reduce loss of heat through the piston. The high thermal conductivity material disposed on the combustion bowl has a surface roughness (R.sub.a) of less than 5 μm to help reflect IR radiation and promote fuel flow. The low thermal conductivity material disposed on the combustion bowl has a surface roughness (R.sub.a) of less than 3 μm to promote fuel flow. The low thermal conductivity material is also disposed on the bowl rim and top ring land, and has a surface roughness (R.sub.a) of greater than 8 μm on the bowl rim and top ring land to retard gas flow.

A piston for an internal combustion engine may include a piston crown and a heat management coating. The heat management coating may be disposed on at least a region of an outer surface of the piston crown. The heat management coating may include a base layer and a functional layer. The base layer may be disposed between the piston crown and the functional layer, and may be adjoining the outer surface of the piston crown. The base layer may have a base layer matrix including a first polysilazane. The functional layer may have a functional layer matrix including a second polysilazane. The second polysilazane may be different from the first polysilazane.