As this is a simple case, you can just create a FEATool Multiphysics toolbox compatible STL file manually, for example with the following code
x = [0 0 0 0 0.1 0.1 0.1 0.1]';
y = [0 0.1 0 0.1 0 0.1 0 0.1]';
z = [0 0 100e-6 100e-6 0 0 50e-6 50e-6]';
DT = delaunayTriangulation(x,y,z);
C = convexHull(DT);
fid = fopen( 'featool.stl', 'w' );
s_fmt = [' facet normal %g %g %g\n', ...
' outer loop\n', ...
' vertex %g %g %g\n', ...
' vertex %g %g %g\n', ...
' vertex %g %g %g\n', ...
' endloop\n', ...
' endfacet\n'];
fprintf( fid, 'solid\n' );
for i=1:size(C,1)
p1 = DT.Points(C(i,1),:);
p2 = DT.Points(C(i,2),:);
p3 = DT.Points(C(i,3),:);
n = cross( p1-p2, p1-p3 );
n = n/norm(n);
fprintf( fid, s_fmt, n, p1, p2, p3 );
end
fprintf( fid, 'endsolid' );
fclose( fid );
However, as this is a very simple geometry and one with very large aspect ratio, it is faster and probably also better to just create the mesh manually directly. For example using the built-in blockgrid and gridrefine commands, one gets
grid = blockgrid( 1, 1, 1, [0 0.1;0 0.1;0 100e-6] );
grid.p(3,[6,8]) = 50e-6;
for i=1:3
grid = gridrefine( grid );
end
plotgrid( grid )
axis normal
Please be aware that the aspect ratio of this geometry is 2000 which is very high, to get good results from your simulations you had better scale the equations in the z-direction correspondingly.
