Actual patent: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PTXT&s1=googl

Actual patent: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PTXT&s1=google.ASNM.&s2=9340178.PN.&OS=AN/google+AND+PN/9340178&RS=AN/google+AND+PN/9340178 http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=H... In short: They propose having a frangible outer layer above the adhesive layer.