• Photosensitive, low dielectric constant materials for electronic packaging and interconnection
• Low-cost packaging of MEMS and other electronic devices
• Sacrificial materials for compliant mechanical structures and ultra low-k electronic applications
• Alkaline fuel cell materials and membranes for platinum-free, efficient cells
• High energy density sodium and lithium batteries

Dr. Kohl’s research interests include new materials and processes for advanced interconnects for integrated circuits and electrochemical devices for energy conversion and storage including lithium ion batteries and alkaline fuel cells.  

Interconnect and Electronic Packaging

The Kohl group has developed new materials and processes for fabrication of embedding air-isolation in electronic and optical devices. Air encapsulated and porous structures provide mechanically compliant, low capacitance interconnects, and can be used for the packaging of microelectromechanical devices. The groups’ other recent projects include chemically amplified permanent photo-dielectrics, electroless copper superfilling, rapid microwave processing of electronic materials, and investigation of novel interconnection materials.

Room Temperature Ionic Liquids

Room temperature ionic liquids provide high conductivity, wide electrochemical stability, and zero vapor pressure. New ionic liquids are simple to produce. The Kohl group is currently developing methods for using electrolytes in high capacity lithium batteries and to deposit dendrite-free lithium metal for a high capacity lithium battery. In addition, ionic liquids are being used at the absorber in a Freon-based absorption refrigeration system where waste heat can be used to provide refrigeration at convenient temperatures and pressures.

High Energy Density Fuel Cells

Methanol can provide the fuel to drive high energy density fuel cells for use in small portable devices. Proton exchange membrane fuel cells have received considerable attention as viable replacements for traditional power sources; however, they have many challenges including complex water management and high cost due to the use of platinum. The Kohl group is researching the use of anions as the conducting species in fuel cells to overcome many of these problems. Additionally, the group has designed fuel cells to overcome water management problems by using new anion conducting membranes that control the water content of the membrane electrode assembly. Progress is also being made toward simple, commercially viable, methanol cells.

Dr. Kohl is a Regents’ Professor, Institute Fellow, Hercules, Inc./Thomas L. Gossage Chair.