Seiko Epson Corporation agreed to invest in printed electronics startup Elephantech Inc., and the parties have entered into a partnership agreement that includes the supply of inkjet printheads.   Elephantech is a startup that manufactures and sells flexible printed circuits (FPC) manufactured using inkjet printing and electroless copper plating.    The company uses a proprietary manufacturing method (Japan patent no. 6300213) in which metal materials are printed only on the required are...