castomize rethinks the orthopedic cast as a breathable '4D-printed' lattice shell

a new generation of orthopedic casts

Castomize is developing a new generation of orthopedic casts in Singapore, using ‘4D-printing‘ to make limb immobilization lighter, cleaner, and easier to adjust. The company’s cast system moves away from the dense, wrapped structure of fiberglass, and toward a pre-made mesh shell that softens with heat, molds directly to the patient’s limb, and hardens again as it cools.

Recently displayed as part of part of PROTOTYPE ISLAND during Milan Design Week 2026, product began as a research project at the Singapore University of Technology and Design before spinning out as a medical technology company in 2022. Its premise is direct, stating that a cast should hold the body securely while allowing skin to breathe, water to pass through, and clinicians to make adjustments without cutting through layers of rigid material.

image via Castomize

a cast that moulds through heat

Castomize’s main product is a re-moldable orthopedic cast made from smart thermoplastic materials and a moisture-resistant inner layer. Each piece is produced in advance, then activated through heat at the clinic. Once warmed, the fibers become flexible enough for a healthcare professional to shape the cast around the patient’s wrist, forearm, elbow, or ankle, depending on the model.

This approach gives the product its ‘4D-printed’ label. The fourth dimension is time: the printed object changes state when exposed to heat, allowing a standardized part to become customized during application. The cast is heated, placed around the limb, clipped into position, and allowed to cool into a firm support structure. The team describes the process as faster and cleaner than conventional casting, with no 3D scan required and no cast saw needed for removal.

image via Castomize

waterproof, ventilated, and made for clinical use

The most visible difference is the open lattice structure. Instead of covering the limb in continuous layers, the Castomize cast uses a perforated shell that allows air to circulate across the skin. The company positions this breathability as one of the product’s main advantages, especially for patients who experience itching, sweating, or irritation under traditional casts.

The cast is also described as fully waterproof, which changes how patients can wash, shower, and move through treatment. The team even notes that the cast can be used while swimming, though medical guidance on this remains in the hands of healthcare professionals. The casts are single-patient devices, but they can be reheated and remolded for the same patient if swelling changes or repositioning is needed.

standardized parts with a customized fit

A key part of Castomize’s design strategy is that the cast does not depend on an individually scanned and printed object for each patient. Instead, the company uses pre-made sizes that become personalized during fitting. This gives the device a different place in the growing field of 3D-printed medical products: it keeps the clinical workflow closer to existing casting, while still using advanced manufacturing to change the object itself.

For clinics, that could mean a simpler adoption path. The cast can be stocked, heated, applied, and adjusted without waiting for a bespoke print. For patients, the experience is shaped by the physical qualities of the finished object: lower weight, visible ventilation, waterproof use, and easier removal.

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