DIY model lungs

How to make a lung model with your own two hands

Safe­ty pre­cau­tions

Warn­ing! Only un­der adult su­per­vi­sion


  • plas­tic bot­tle with cap;
  • scis­sors;
  • sta­tionery knife;
  • 3 bal­loons;
  • 2 nar­row straws;
  • 1 wide straw;
  • ad­he­sive tape;
  • sealant.

Step-by-step in­struc­tions

In­sert two nar­row straws into a wide straw and se­cure with ad­he­sive tape. Trim them to fit the size of the bot­tle they’ll go in. Then cut the tails off of two bal­loons and tape the bal­loons to the ends of the nar­row straws. Pre­pare a plas­tic bot­tle: make a hole to fit the large straw in the bot­tle cap, and cut the bot­tom off the bot­tle. Pass the large straw through the hole and seal it in place. In­sert the “lungs” through the bot­tle­neck and screw the cap on tight­ly. To make the di­aphragm, put the struc­ture up­side down in a glass and stretch an­oth­er trimmed bal­loon over the bot­tom of the bot­tle. Ob­serve how the bal­loons in the bot­tle in­flate and de­flate as you push and pull on the di­aphragm!

Process de­scrip­tion

The lungs serve as the res­pi­ra­to­ry or­gans for hu­mans and many oth­er an­i­mals. They ex­tract oxy­gen from the air and trans­fer it to the blood­stream. They also ex­pel car­bon diox­ide. In this ex­per­i­ment, the bal­loons on the straws act as the lungs, the straws act as the tra­chea, the bot­tle serves as the chest, and the bal­loon at the bot­tom of the bot­tle is the di­aphragm. When the di­aphragm is pulled, the pres­sure in the bot­tle be­comes low­er than at­mo­spher­ic pres­sure, and the bal­loon “lungs” in­flate. When the di­aphragm is pressed, the pro­cess­es re­verse. Real lungs work sim­i­lar­ly: when the di­aphragm con­tracts, the vol­ume of the chest cav­i­ty in­creas­es and air fills the lungs. Please note that this is a sim­pli­fied mod­el of the lungs and does not take into ac­count the move­ment of the in­ter­costal mus­cles.

In­for­ma­tive ex­per­i­ments await you in the MEL Chem­istry sub­scrip­tion!