<s>
Undercuts	B-Algorithm
from	O
etching	B-Algorithm
(	O
microfabrication	O
)	O
are	O
generally	O
an	O
unwanted	O
side	O
effect	O
,	O
however	O
are	O
sometimes	O
used	O
as	O
a	O
feature	O
such	O
as	O
in	O
the	O
Niemeyer	B-Algorithm
–	I-Algorithm
Dolan	I-Algorithm
technique	I-Algorithm
.	O
</s>
<s>
Undercuts	B-Algorithm
from	O
etching	B-Algorithm
can	O
occur	O
from	O
two	O
common	O
causes	O
.	O
</s>
<s>
The	O
first	O
is	O
over	O
etching	B-Algorithm
,	O
which	O
means	O
the	O
etchant	O
was	O
applied	O
too	O
long	O
.	O
</s>
