Origami based on physics

O­ri­ga­mi—the gen­tle Jap­a­nese art of
fold­ing pa­per in­to lit­tle sculp­tures—is tak­ing on some
high-pow­ered roles late­ly. Phys­i­cists have been us­ing it to solve
an ar­ray of prob­lems in fields rang­ing from tel­e­scope phys­ics to
med­i­cine.
Wa­ter Strid­er, opus 472
by Rob­ert J. Lang. Com­posed of one un­cut square of Ori­ga­mi­do pa­per in
2005.
Rob­ert J. Lang,
an ori­ga­mi art­ist and form­er phys­i­cist based in Al­a­mo, Ca­lif.,
de­scribed some of the work in an ar­ti­cle in the Feb­ru­ary is­sue of
Phys­ics World mag­a­zine. 
“In the last few dec­ades sci­en­tists and en­gi­neers have be­gun
in­ves­ti­gat­ing the sur­pris­ing­ly rich math­e­mat­ics un­der­ly­ing
ori­ga­mi, and along the way have found a wide range of ap­pli­ca­tions
for the an­cient art,” he wrote.
“Although there are still rel­a­tively few spe­cial­ists in
sci­en­tif­ic ori­ga­mi, there are enough to fill a good-sized
con­fer­ence hall. Rough­ly once eve­ry five years since 1989 these
ex­perts have or­gan­ized an in­ter­na­tion­al meet­ing,” most
re­cent­ly at the Cal­i­for­nia In­sti­tute of Tech­nol­o­gy last
Sep­tem­ber.
Ori­ga­mi com­mon­ly uses a sin­gle, un­cut square of pa­per, from
which the art­ist fash­ions an ar­ray of shapes mere­ly by fold­ing.
Such strict lim­i­ta­tions might seem to place a tight cap on how many
de­signs can be made, Lang wrote, but in the 1970s math­e­mati­cians
found that the num­ber was vir­tu­al­ly end­less.
Tes­se­la­tion, by Rob­ert J.
Lang. The reg­u­lar ar­ray of square twists il­lus­trates the way ori­ga­mi can
be used to cre­ate com­plex de­signs that fold in and out in on­ly one,
pre­de­fined way. This can be use­ful in sci­en­ti­fic
ap­pli­ca­tions. Com­posed in 1999. 
Sci­en­tists have put the
prin­ci­ples of ori­ga­mi to prac­ti­cal ap­pli­ca­tion since the
1990s, he added. Of­ten it comes in handy for ob­jects that need to be
col­lapsed in­to a small space dur­ing trans­port to some suit­a­ble
lo­ca­tion, then re-o­pened au­to­mat­i­cally.
That fi­nal lo­ca­tion can vary wide­ly—from or­bit around Earth, to an ar­tery in the body, for ex­am­ple.
The Space Flight Unit, a Jap­a­nese sat­el­lite launched in 1995, used
so­lar pan­els that folded and un­folded ac­cord­ing to an
ori­ga­mi-based pat­tern called Miura-ori, which had al­so been
iden­ti­fied in nat­u­ral struc­tures such as leaves. 
The sys­tem was de­signed to en­sure that as soon as one joint was opened, the whole thing
would un­furl in a pre­de­fined way, re­duc­ing chances of mis­takes dur­ing unfold­ing in space.
A model for an ori­ga­mi stent,
in
stain­less steel. Its width ex­pands from 12 mm to 23 mm. In prac­tice,
flex­i­ble ma­te­rials are best in place of steel, the
makers say. (Cour­te­sy K.
Ku­ri­ba­ya­shi, Z. You/Uni­ver­sity of Ox­ford)
In the ear­ly 2000s, re­search­ers
at Ox­ford Uni­ver­si­ty, U.K. de­vel­oped an anal­o­gous con­cept for
a heart stent, a ti­ny tube placed in a blocked ar­tery to prop it open
and re­store blo