A conceptual design of two-stream alkali-activated materials

To properly control the reaction kinetics and fresh properties evolution in conventional alkali-activated materials (AAMs), a conceptual design of two-stream AAMs has been proposed in this study. This is achieved by dividing the solid and liquid components in AAMs, including blast furnace slag (BFS) and electric arc furnace slag (EFS)...

3D-printing allows for fluid-controlled linear actuators with unconventional shapes

Background: Pneumatic actuators are widely used in applications like (medical) robots, or prostheses. Pneumatic actuators require a complex manufacturing process and are produced in standardized dimensions to reduce costs. Over the last decade 3D-printing has emerged as a cost-effective and efficient production method in medical applications....

Focus Raqqa: Inventory of Museum Collections and Reconstruction of Missing Tablets

The National Museum of Raqqa in Syria has suffered immensely from the ongoing violence since 2011. Much of its valuable collection of movable archaeological heritage (ca. 6000 items) is considered lost. Starting from 500 of the most precious objects of the museum stored in the Raqqa Central Bank and stolen from there in 2013, the pilot project...

Broadband Waveguide Characterization of 3D-Printed Anisotropic Dielectric Crystals

Additive manufactured structured dielectrics with engineered permittivity tensors are promising tools for novel microwave components and are drawing increasing attention from researchers. However, design modeling and experimental verification of anisotropic materials are challenging and have not yet been thoroughly explored in the literature. In...

Fluidic Force Microscopy and Atomic Force Microscopy Unveil New Insights into the Interactions of Preosteoblasts with 3D-Printed Submicron Patterns

Physical patterns represent potential surface cues for promoting osteogenic differentiation of stem cells and improving osseointegration of orthopedic implants. Understanding the early cell–surface interactions and their effects on late cellular functions is essential for a rational design of such topographies, yet still elusive. In this work...

Pseudo rigid body model for a nonlinear folding compliant mechanism

Folding compliant mechanisms have the potential to be used for innovative designs tailored for specific applications such as energy absorption, shape morphing, or stress relief. This tailorability relies on multiple variables that define the geometric and material behavior. The combined effort of the geometric and material nonlinearity can...

Ceramic-faience hybrids were used to recycle bronze in North-Western European Iron Age egg-shaped crucibles

We investigated the characteristics of a group of 13 Middle Iron Age egg-shaped crucibles and crucible fragments from Tilburg (The Netherlands). We used a combination of optical and chemical analyses, including hand-held XRF, microCT scanning and 3-D printing polarizing light microscopy and SEM-EDX. The chemical analyses confirmed that the...

Proportional Microvalve Using a Unimorph Piezoelectric Microactuator

Microvalves are important flow-control devices in many standalone and integrated microfluidic applications. Polydimethylsiloxane (PDMS)-based pneumatic microvalves are commonly used but they generally require large peripheral connections that decrease portability. There are many alternatives found in the literature that use Si-based microvalves,...

Anisotropic Stiffness Adhesives for High Shear Forces on Soft Substrates

Reversible attachment on soft substrates is useful in a range of applications, including soft robotics and soft-tissue surgical instrumentation. On rigid substrates, the use of micropatterned adhesives has been extensively explored. It has been shown that surface micropatterns provide conformability, thereby enabling the formation and...

Proportional Microvalve Using A Piezoelectric Unimorph Microactuator

Microvalves are important flow-control components in many standalone and integrated microfluidic circuits. Although there is a large body of work regarding<br/>microvalves, there is still a need for an easyto-fabricate, small-footprint, low-power device that can control both liquids and gases at moderate pressures. This paper details the...

Design of a novel three- dimensional-printed two degrees-of-freedom steerable electrosurgical grasper for minimally invasive surgery

In current bipolar electrosurgical instruments, a high frequency electrical sinusoidal wave is passed through the patient's body from an active electrode to the return electrode to cut, coagulate, or desiccate tissues. Even though current bipolar electrosurgical instruments have proven effective in minimizing blood loss, advancement is needed...

3D-printed upper limb prostheses: a review

Goal: This paper aims to provide an overview with quantitative information of existing 3D-printed upper limb prostheses. We will identify the benefits and drawbacks of 3D-printed devices to enable improvement of current devices based on the demands of prostheses users. Methods: A review was performed using Scopus, Web of Science and websites...

The structural feasibility of 3D-printing houses using printable polymers

At this point in time, 3D-printing techniques in general, but especially applied for the building industry, still are in a phase of early experiments. One of the experimental attempts is to print a full-scale, three-story high, house in Amsterdam, using an up scaled version of a FDM-printer that is able to print blocks of 1.8 x 1.8 x 3.0 meters...