Singapore-based medical technology company Castomize has developed a series of 4D printed orthopaedic casts that combine lightweight structures, smart materials and additive manufacturing. The casts offer an alternative to conventional fibreglass immobilisers and focus on comfort, breathability and easier application.

Lightweight Casts With A Breathable Structure

Castomize uses a lattice mesh design that improves airflow around the skin. This open structure helps reduce sweating, itchiness and discomfort, which are common issues with traditional casts. The casts are also fully waterproof, allowing users to shower or swim without damaging the material.

Each device weighs around 200 grams and consists of a waterproof outer shell combined with a moisture-resistant inner fabric. The company currently produces short-arm, long-arm and ankle immobilisers, with paediatric versions under development.

Smart Thermoplastics Enable Remoulding

The casts are made from a proprietary blend of skin-safe thermoplastics that become flexible when heated. Healthcare professionals can heat the cast, mould it directly to the patient’s limb and secure it within minutes. Once cooled, the material hardens and provides the required support.

Unlike traditional fibreglass casts, the devices can be removed and reshaped without using a cast saw. Integrated clips allow the cast to open and close easily, which can improve patient comfort and reduce material waste during treatment adjustments.

Castomize refers to the process as “4D printing” because the material changes shape in response to heat. The technology removes the need for 3D scanning and supports faster application with fewer fitting errors.

Additive Manufacturing For Medical Design

The company combines data-driven design methods with in-house additive manufacturing technologies. According to Castomize, thousands of data points help optimise the geometry of each cast. The designs are then refined through collaboration with healthcare and engineering specialists.

The thermoplastic materials are ISO 10993 certified for biocompatibility and registered as Class 1 medical devices in Singapore, South Korea, Taiwan and Australia. Castomize is also exploring future applications in prosthetics and veterinary healthcare.

The project demonstrates how additive manufacturing and advanced material development are creating new opportunities in healthcare design. By combining remouldable polymers with lightweight structures, the casts aim to improve both patient experience and clinical efficiency while reducing the limitations of conventional immobilisation systems.

Source & photos: Castomize