I made a robot that walks with Jansen's mechanism and uses ordinary materials. The Jansen's linkage is a leg mechanism designed by the kinetic sculptor Theo Jansen to simulate a smooth walking motion.

Step 1: Materials

A4 cardboard
Scissors
Glue
Hot glue (optinal)
Tooth picks
Drinking straws
AA battery holder
AA Batteries
On/Off switch or 3 position switch with 6 pins
Wires
Electrical terminal connectors
Bicycle spokes (or hard wire)
metal washers
6V gearmotor(about 60rpm)
Galvanized plate (about 10 x 10 cm)
MechaRobo assistant (optional)

Step 2: Motorbase

Cut a rectangular plate about 10 x 5 cm and fix gearmotor with an U shape bridge on it

Solder two bike spoke on base, the distance between spokes must be 8.5 cm. The rotary shaft of gearmotor must be about 8 mm over the base.

Step 3: Legs (segment A)

Download pattern
Print pattern on the cardboard
Cut A segment, fold and glue as shown

LEGS.pdf
Download

Step 4: Legs (segment B)

Cut B segment, fold and glue as shown
Use three tooth picks for the reinforcement moving part
Cut F segment, fold and glue. use two metal washers for reinforcement
Puch F segment and fix to B Segment as shown

Step 5: Legs (segment C)

Cut C segment and fold
Puch and make a hole
Place and keep a drinking straws in hole and glue as shown

Step 6: Legs (segment D)

Cut D segment, fold and glue as shown.

Step 7: Connecting Segments

Connect segments A,B,C and D together
Use two strip to connect segment B to other segments
Make other three legs

Step 8: Tail Base

Cut a rectangular plate about 10 x 2 cm
Solder three electrical termial connectors on the base

Step 9: Crankshaft

Use a bike spoke to make crankshaft
Make crankshaft straight as possible
Pass crackshaft through the hole of washers as shown on picture

Step 10: Connecting Legs to Gearmotor

Use an electrical terminal connector to connect crankshaft to gearmotor
Connect tail base to bike spokes and Screw it
Dont screw crackshaft to tail base

Step 11: Wiring

Fix battery holder on tail base with glue
Wiring battery holder, gearmotor and switch as shown
If you want bi-directional movement, you can use a 3 position switch with 6 pins instead of on/off switch.

Bi-directional wiring: