Example of using emoji for author marks in IEEETran

emojiauthor.tex

% This is for IEEEtran but should give an idea of how to do it for other styles
% Preamble
\usepackage{emoji}

% [...]

% This is the main piece; we just redefine the IEEEauthorrefmark command and
% replace the symbols. We have to remove the \ensuremath{} because emoji don't
% seem to work in math mode. You can of course replace these emoji with any of
% the ones defined by the emoji package:
% https://ctan.math.washington.edu/tex-archive/macros/luatex/latex/emoji/emoji-doc.pdf

\DeclareRobustCommand*{\IEEEauthorrefmark}[1]{\raisebox{0pt}[0pt][0pt]{\textsuperscript{\footnotesize%
    \ifcase#1\or \emoji{thinking-face}\or \emoji{zany-face}\or \emoji{face-with-raised-eyebrow}\or%
    \emoji{grimacing-face}\or \emoji{relieved-face}\or \emoji{face-with-spiral-eyes}\or%
    \emoji{exploding-head}\or \emoji{partying-face}\or \emoji{smiling-face-with-sunglasses}\or%
    \emoji{loudly-crying-face} \else\textsuperscript{\expandafter\romannumeral#1}\fi}}}
 
% Then just write your author block as normal:
\author{\IEEEauthorblockN{%
  First Author\IEEEauthorrefmark{1} and %
  Second Author\IEEEauthorrefmark{2} %
  }\\
\IEEEauthorblockA{Generic University\\
Email: \IEEEauthorrefmark{1}first@example.edu, %
 \IEEEauthorrefmark{2}second@example.edu %
}}