If the survey is expired, I like to print out the current survey title, but the {{ aSurveyInfo.surveyls_title }} is emtpy.

Any tricks to get the title info?

Try with {{ processString("{SURVEYNAME}") }}

and please : report the issue : community.limesurvey.org/bug-tracker/

{{ processString("{SURVEYNAME}") }} doesn't work too.

i will report it.

I see you report it
bugs.limesurvey.org/view.php?id=16880

Please : when you report an issue : give more details : more details you give, more easy to fix.
You can add the information about processString too