# Reprogrammable Origami Lab

By greenlig

Topic: Art, Music & Film

[Open the interactive Jig](https://ask.jig.com/j/5RArhOTS3SjB)

## Guide

### 1. A fold that can change its mind

This bench tests one hinge from a real research paper\. Two plastic panels meet at a tape hinge, and a thin steel strip spans the gap\. That strip decides which way the hinge likes to fold\.

Paper: Kamp et al\., Reprogrammable origami through bistable buckled hinges \(Harvard\)\.

### 2. The springy steel shim

The strip, called a shim, is a little longer than its gap, so it bows into an arch\. It has two resting shapes: bowed up or bowed down\. Press it and it snaps over\.

Gap 15 mm, shim 0\.05 mm thick: thinner than a hair \(p\.3\)\.

### 3. Soft one way, stiff the other

The bench turns the hinge back and forth and the gauge reads the twisting force\. Bowed up, the hinge folds easily as a mountain and resists a valley\. Flip the shim and the favourite direction swaps\.

The paper measured about 4\.3 times more stiffness one way at 65 degrees \(p\.3\)\.

### 4. Three agents, one test

Each module on the bench is an agent using a different method on the same hinge\. The beam agent bends a model strip, the paper\-data agent rebuilds the curve from reported numbers and the design agent solves for two shims\. The same gauge and plot measure them all\.

Press a module to put its curve in bold\. Dashed curves are unverified\.

### 5. Squeeze it to set the angle

A longer shim in the same gap bows more, so the hinge settles at a steeper resting angle\. The d/L dial is gap length divided by shim length\. Watch the dot where each agent finds zero force\.

Paper: d/L from 1\.0 down to 0\.3 gives rest angles from 0 to almost 180 degrees \(p\.5\)\.

### 6. Move it over, and it snaps

Slide the shim off the hinge line and turning the hinge the stiff way makes it suddenly snap to its other shape\. The force drops at once\. The further it is moved, the earlier it snaps\.

Paper: 68 degrees at a 5 mm offset with d/L 0\.75 \(p\.7\)\. Crosses mark snaps\.

### 7. Two shims, two shapes

Put two shims of different widths in one hinge and it can rest at two chosen angles\. The design agent solves for a hinge that folds one way for a bird and another way for a whale\.

Paper targets: \-145 and 45 degrees; built hinge: \-149 and 48 \(p\.6\)\.

### 8. What the lab checked

Every agent was checked against numbers printed in the paper\. Green lamps match within the stated tolerance; amber lamps mark differences or results nobody could verify\. A simple model can show the idea and still miss the numbers\.

Full table with page references: authoring/verification\.md in the source\.