Massachusetts Institute of Technology

Desktop Metal, Inc.

Uwe Bauer

Emanuel Michael Sachs

Geoffrey S D Beach

Nicholas Graham Bandiera

Jonah Samuel Myerberg

Mark Gardner Gibson

For conditioning build material for fused filament fabrication, thermal power is both added to and removed from a nozzle in a manner that can reduce sensitivity of the nozzle temperature to fluctuations in build material feed rate. The amount of thermal power added is at least as large as the sum of the amount removed, the amount to condition the material, and losses to the environment. The amount removed may be at least as large as half the thermal power required to condition the material to extrusion temperature, and may be comparable to, or much larger than the conditioning amount. The larger the ratio of the amount removed to the conditioning amount, the less sensitive the nozzle temperature will be to fluctuations in build material feed rate. Fine temperature control arises, enabling building with metal-containing multi-phase materials or other materials that have a narrow working temperature range.

Thermally robust nozzle for 3-dimensional printing and methods of using same

3D printing using certain materials, such as metal containing multi-phase materials can be prone to clogs and other flow interruptions. Providing build material according to feed rate profiles having varying rates can mitigate these problems. Each feed rate profile can be broken up into blocks of time, some of which relate to fabricating the exterior geometry of the object. Each block of time can be represented by a FFT. The blocks that relate to the exterior are represented by a FFT that has significant high frequency content of 1 Hz or greater. It is beneficial to use profiles including feed rates outside of a range of feed rates suitable for steady state extrusion, being either higher or lower rates than the range limits. A combination of feed rate profiles based only on clog and flow interruption mitigation and operational to print the part according to a model can be used.

Additive fabrication using variable build material feed rates

Systems, methods, and apparatus are provided for tuning a memristive property of a device. The device () includes a layer of a dielectric material () disposed over and forming an interface with a layer of an electrically conductive material (), and a gate electrode () disposed over the dielectric material. The dielectric material layer includes at least one ionic species () having a high ion mobility. The electrically conductive material is configured such that a potential difference applied to the device can cause the at least one ionic species to migrate reversibly across the interface into or out of the electrically conductive material layer, to modify the resistive state of the electrically conductive material layer.

Voltage-controlled resistive devices

Systems, methods, and apparatus are provided for tuning a functional property of a device. The device () includes a layer of a dielectric material () disposed over and forming an interface () with a layer of an electrically conductive target material (). The dielectric material layer includes at least one ionic species having a high ion mobility. The target material is configured such that a potential difference applied to the device can cause the at least one ionic species to migrate reversibly across the interface into or out of the target material layer. The mobility of the at least one ionic species can be tuned by exposing the device to electromagnetic radiation and/or a temperature change.

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Cambridge, MA, United States of America

Uwe Bauer