Agilista 3000

The implantable chamber device was a tube-shaped acrylic structure with a length of 3.0 mm and inner and outer diameters of 2.5 and 3.3 mm, respectively (Figure 1b). We used FreeCAD 0.16 software to design the tube structure and fabricated it using a high-resolution three-dimensional (3D) printer (AGILISTA-3000; Keyence, Osaka, Japan). We used a semipermeable atelocollagen membrane sheet (CLF-01; KOKEN, Tokyo, Japan) as the dura substitute. Atelocollagen is a low-immunogenic derivative of type I collagen obtained by removing the N- and C-terminal telopeptide components and is regarded as a highly biocompatible biomaterial. The membrane sheet can be cut into any shape and size, and has a thickness of 35 μm. One end of the tube structure was sealed by the collagen membrane using biocompatible adhesive (Aron alpha A; Sankyo, Tokyo, Japan). The sealed side of the tube device was gently pressed against the cortical surface [20 (link)].

As an experimental setup to demonstrate chemical-source-direction estimation using the proposed device, we fabricated a device to release a chemical solution (the chemical-solution-flow device). The device was mounted on a dish and able to eject a chemical solution from a release port 8.5 mm away from the center of the dish, thereby leading to the generation of chemical-solution flow from the port in the dish (Supplemental Figure 1). The chemical-solution flow was also observable owing to a window opened near the center of the device to allow access to a microscope. The device was prepared with a 3D printer (AGILISTA-3000, Keyence, Japan) and subsequently washed with water to remove the resin on its surface.

The plastic skeletons were designed by CAD software (Autodesk Inventor Professional 2019; https://www.autodesk.com/products/inventor/). Handles were designed on both ends of the geometric part. The geometry of the skeleton excluding the handles had a width of 24.5 mm, length of 60 mm, and thickness of 2 mm (Figure S1a). The functional geometries (auxetic, offset rectangle, and honeycomb) were designed by changing the angle (θ = 40°–140°) of the joints (Figure S1b). All interconnects have a width of 0.5 mm. A spacer was designed around the exterior of the skeleton to fix the skeleton in the middle of the matrix and maintain a total composite thickness of 4 mm and was removed prior to sample testing. These designed skeletons were 3D printed (AGILISTA-3000, Keyence Co.). After printing, the skeletons were washed in deionized water to remove the support material and dried.