A small plastic object can be seen in front of the tip of a hypodermic needle. The object is made of clear, slightly purple-tinted plastic. It is roughly circular, with edges thicker than the center.

The Latest From RepRapMicron – Nail Gel, First Objects, And More

We’ve been following [Vik Olliver]’s progress on the μRepRap project with interest for some time now. The project’s goal is to build a 3D printer that can print feature sizes down to about 10 microns – the same feature size used in the Intel 4004 processor. At the recent Everything Open 2026 conference, [Vik] presented an overview of all the progress he’s made in the last year, including printer improvements, material woes, and the first multi-layer prints (presentation slides).

The motion stage has undergone some fundamental improvements recently. The original XY motion table was supported on four flexures which allowed movement in X and Y, but also introduced slight variations in Z – obviously a problem in a system that needs to be accurate down to the microns. The latest version now uses complementary flexures to maintain a constant Z height, and eliminates interference between the X and Y axes. The axis motion drivers were also redesigned with parallel-bar linear reducers inspired by a pantograph, increasing their usable range from two to eight millimeters.

Rather than extruding material, the μRepRap uses an electrochemically-etched needle point to deposit UV-curable gel on the build surface. [Vik] found that a bit of nitric acid in the needle etching solution gave the edges of the probe a bit of a rough texture which let it hold more resin. He started his test prints using normal 3D printer resin, but it turns out that dissolved oxygen inhibits curing – quite a problem for small, air-exposed droplets. Fortuitously, UV nail gel does cure in air, and the next set of tests were printed in nail gel, including the first layered prints (one of which can be seen above, on top of a hypodermic needle). The μRepRap can’t yet print large numbers of layers, but [Vik] did print some hinged parts that could be folded into shape.

There’s much more in the presentation than can be covered here, including some interesting thoughts about the possibility of 3D printing electrochemical memory cells in ionic gel. Near the end of the presentation, [Vik] listed some pieces of related work, including necroprinting and this homemade micro-manipulator.

 

Flexure PCB Actuators Made Before Your Very Eyes

When we see something from [Carl Bugeja], we expect to see flexible PCBs and magnets being pushed to do unexpected things. His latest video in which he designs a set of PCB actuators using flexure joints certainly doesn’t fail to please.

His intent is to create a simple actuator in which a magnet is placed over a coil, and moves upward within the confines of he flexure which surrounds it. And rather than try individual designs one after the other he’s created a huge all-in-one test array of different flexure actuators, each having a slightly different design and construction to whichever one is next to it. There are plenty of magnet flips as he tests them, and using this approach he’s quickly able to eliminate the designs which work less well.

To give an idea how these actuators might be best used, he tried them in a few applications. Their lifting force is relatively tiny, but he found them possibly suitable for a haptic feedback device. Of particular interest is that as the structure is a PCB it’s relatively straightforward to run a line to the magnet and turn it into a touch sensor. The idea of an all in one sensor and haptic feedback component is rather appealing, we think.

If you’ve not seen Carl’s work before, we’ve encountered him many times over the years.

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