Petit Flip Flop

Inspired by Petit Pli’s clothing line for children. Petit Flip Flop is a more sustainable flip flop for children aged from 1 to 4 years old. Utilising a unique design, which is only possible to make with additive manufacturing technology, Petit Flip Flop grows with the child meaning that they can use 1 Flip Flop instead of many. Petit Flip Flop is an alternative to fast fashion. Through its use of an expandable design, it is much better for the environment.

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//Expandable Lattice Design
The most unique part of the Petit Flip Flop is the origami-inspired expandable sole design. This is fulfilled through the use of a dual-layer polygonal lattice which can hinge in two directions. When the lattice is pulled from one end, along its length, and stretched it will also increase in width. This is useful as it means the sole will match the Child’s foot length and width.

The bottom layer is made up of larger units as these give the flip flop rigidity. The top layer of the lattice unit is made up of a greater number of smaller units to provide more surface area for the foot resting on the surface. Since the pattern is the same for both layers, they have the same ratio of expansion so will always line up.

//Strap Design
The 3d printed strap is crucial for the design. As well as holding the Child’s foot, this part also controls the expansion level of the flip flop through adjustment of the heel strap. It attaches to the front of the sole and wraps around the rest of the flip flop.

The fastening connectors for the straps are printed as part of the product. The fasteners are a shape that could not be injection moulded as the diameter increases towards the top forming an inverse draft angle. Surfaces with the fasteners on can then easily and strongly connect to each which is good for a child to be able to use them easily. Integrating this functionality reduces final flip flop cost as less assembly time and work is needed to manufacture a flip flop.

Expansion Ratio = 0
Age = 1 year old

Expansion Ratio = 0.5
Age = 2.5 year old

Expansion Ratio = 1
Age = 4 year old

Throughout the 4 years of use of the flip flop, the sole will expand as the Child’s foot grows larger. This is achieved through the unique strap design which compresses the sole along its length by tightening up the fastener at the heel of the foot. A diagram showing the different levels of lattice expansion can be seen below.

//Tools Used
+ Additive Design Methodology
+ Fusion 360
+ Blender
+ Indesign
+ Formlabs flexible resin
+ March 2020