Development of nuclear emulsions with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si0011.gif" overflow="scroll"><mml:mn>1</mml:mn><mml:mspace width="0.25em"/><mml:mi mathvariant="normal">μ</mml:mi><mml:mi mathvariant="normal">m</mml:mi></mml:math> spatial resolution for the AEgIS experiment