Unicode characters do not appear in IEEE style bibliography

Question

I cannot get Unicode characters to appear in the IEEE style bibliography with biblatex and biber. Shown below are minimal working examples.

\documentclass[journal]{IEEEtran}

\usepackage[style=ieee, bibencoding=utf8, backend=biber]{biblatex}
\usepackage[utf8]{inputenc}
\addbibresource{Bibliography.bib}

\begin{document}

\nocite{lee12b}
\renewcommand*{\UrlFont}{\rmfamily}
\printbibliography

\end{document}

And here are the contents of the .bib file. Note the following Unicode characters: µ (Greek mu) and ° (degree sign).

% Bibliography.bib
@article{lee12b,
    Author = {Lee, Junghyup and Cho, SeongHwan},
    Date-Added = {2013-01-23 07:05:03 +0800},
    Date-Modified = {2013-02-11 13:58:24 +0800},
    Doi = {10.1109/JSSC.2012.2204475},
    Issn = {0018-9200},
    Journal = {Solid-State Circuits, IEEE Journal of},
    Month = {Oct},
    Number = {10},
    Pages = {2527--2533},
    Printed = {1},
    Title = {{A 1.4-µW 24.9-ppm/°C Current Reference With Process-Insensitive Temperature Compensation in 0.18-µm CMOS}},
    Volume = {47},
    Year = {2012},
    }

Answer 1

The problem is inputenc - this doesn't cover the full range of UTF-8. If you change the inputenc line to

\usepackage{fontspec}

and then use Lualatex or Xelatex instead of PDFlatex, your example works fine.

The other option is to keep your example as it is and use pdflatex as normal but add:

\usepackage{textcomp}

and run biber like this:

biber --output_safecharsset=full --output_safechars <file.bcf>

which will convert the difficult characters which inputenc can't deal with into TeX macros. The textcomp package loads the macro definitions to deal with the macros which biber converts to (in this case, the \textdegree macro).