From source article:
Vicknes Waran from the University of Malaya in Kuala Lumpur, Malaysia, and colleagues created the model using the latest generation of 3D printers, which can print plastic in a variety of textures, from rubbery to hard. By tweaking the printer's settings, they mimicked the consistency of skin, bone and membranes to build up the layers inside a skull. To reproduce a jelly-like tumour, plastic was injected into an anatomically accurate cavity created by the printer, based on scans from a patient. It was then coloured red to add realism.
The skull is an improvement over existing models that use a single material because it allows trainees to see, feel and even hear how each type of tissue responds. Patient-specific replicas can simulate different medical conditions, allowing students to rehearse an entire operation ahead of time.
The researchers also made models of the head. These can be reused, but the model brains with internal structure are custom-made for each practice session. Each costs about $600 to make, which makes it an affordable option.
The team has already created even more sophisticated model brains with cavities that students can probe. "It bleeds and has fluid for brain endoscopy," says Waran.