Ohio State Innovation Foundation

University of Notre Dame Du Lac

University of California

David John Hoelzle

Nathaniel Joseph Wood

Amy Rowat

Clara Chan

Siyuan Zhang

Jeremiah Zartman

Cody Narciso

Ali Asghari Adib

Wendy Alvarez Barrios

Victoria Zellmer

Desmond M D'Souza

Desmond M D′souza

Estimation algorithms, methods, and systems are provided that estimate the internal temperatures inside of a part being built using powder bed fusion (PBF). Closed-loop state estimation is applied to the problem of monitoring temperature fields within parts during the PBF build process. A simplified linear time-invariant (LTI) model of PBF thermal physics with the properties of stability, controllability and observability is presented. In some aspects, Model Predictive Control (MPC) may be used as an expanded application of an Ensemble Kalman Filter (EnKF) methods to control the PBF process. MPC is used to forecast the PBF build process behavior N time steps into the future and identifies inputs that drive the temperature of a corresponding node in a mesh of n nodes towards a predetermined target temperature.

Model predictive control (MPC) for controlling internal temperature distributions within parts being manufactured via the powder bed fusion process

Estimation algorithms, methods, and systems are provided that estimate the internal temperatures inside of a part being built using a Finite Element Method (FEM)-based thermal model of Powder Bed Fusion (PBF) heat transfer. Closed-loop state estimation is applied to the problem of monitoring temperature fields within parts during the PBF build process. The PBF laser is very small, therefore, so too are the FEM elements nearby the laser. Thus, as the PBF laser moves, a region of high mesh density moves along with it as it progresses over a geometry. In an aspect, regions of high mesh density are predetermined for each time step according to a predefined schedule of laser movements.

Adaptive FEM meshing for estimating internal temperature distributions within parts being manufactured via the powder bed fusion process

The present disclosure provides methods for freeform extrusion-based additive manufacturing via a robotic arm. In specific aspects, methods are particularly provided for minimally invasive, intracorporeal three-dimensional printing of biocompatible materials. An end effector of a robotic arm includes a sharp member and a reservoir filled with a printing material. The provided method may include piercing a substrate with the sharp member. A bulb or micro-bolus of material may be extruded beneath the substrate surface to act as an anchor. The end effector may be manipulated to extrude biomaterial along a printing path. Periodically along the printing path, the sharp member is used to pierce the substrate surface create additional respective anchors. In some instances, the method may terminate after extruding material to form a single layer construct. In other instances, the method includes forming one or more layers on top of the initial base layer anchored to the substrate.

Additive manufacturing methods utilizing a robotic arm

An additive manufacturing (AM) device for biomaterials comprises a reservoir, a shaft, and a material delivery head. The device can be used for intracorporeal additive manufacturing. Material within the reservoir can be expelled by a mechanical transmission element, for example a syringe pump, a peristaltic pump, an air pressure pump, or a hydraulic pressure pump. The reservoir can be a barrel, a cartridge, or a cassette. The reservoir can narrow into the shaft, and the shaft can terminate into the nozzle. The shaft can house an inner tube. The device can have an actuator joint capable of being mechanically linked to a robotic surgical system. The actuator joint can have a motor that drives the mechanical transmission element.

Additive manufacturing device for biomaterials

The present disclosure provides methods for freeform extrusion-based additive manufacturing via a robotic arm. In specific aspects, methods are particularly provided for minimally invasive, intracorporeal three-dimensional printing of biocompatible materials. An end effector of a robotic arm includes a sharp member and a reservoir filled with a printing material. The provided method may include piercing a substrate with the sharp member. A bulb or microbolus of material may be extruded beneath the substrate surface to act as an anchor. The end effector may be manipulated to extrude biomaterial along a printing path. Periodically along the printing path, the sharp member is used to pierce the substrate surface create additional respective anchors. In some instances, the method may terminate after extruding material to form a single layer construct. In other instances, the method includes forming one or more layers on top of the initial base layer anchored to the substrate.

Estimation algorithms, methods, and systems are provided that estimate the internal temperatures inside of a part being built using powder bed fusion (PBF). Closed-loop state estimation is applied to the problem of monitoring temperature fields within parts during the PBF build process. A simplified linear time-invariant (LTI) model of PBF thermal physics with the properties of stability, controllability and observability is presented. In some aspects, an Ensemble Kalman Filter is applied to the model. Linear time-varying (LTV) systems are also contemplated.

Estimating internal temperature distributions within parts being manufactured via the powder bed fusion process

This invention provides methods and devices for the high-throughput characterization of the mechanical properties of cells or particles. In certain embodiments the devices comprise a micro fluidic channel comprising: an oscillating element on a first side of said channel; and a detecting element on a second side of said channel opposite said oscillating element, wherein said detecting element is configured to detect a force transmitted through a cell or microparticle by said oscillating element. In certain embodiments the devices comprise a microfluidic channel comprising an integrated oscillator and sensor element on one first side of said channel, wherein said sensor is configured to detect a force transmitted through a cell or microparticle by said oscillator.

Mechanical phenotyping of single cells: high throughput quantitative detection and sorting

One aspect of the present disclosure can include a microfluidic device for imaging a tissue sample. The device can include a tissue chamber, a liquid inlet channel, and a liquid outlet channel. The tissue chamber can be defined by a plurality of walls, at least one of which is transparent. The liquid inlet channel can be fluid communication with the tissue chamber. The liquid outlet channel can be in fluid communication with the tissue chamber. The tissue chamber can be sized and dimensioned to completely immobilize the tissue sample during imaging.

Microfluidic devices, systems, and methods for imaging tissue samples

A microfluidic device for evaluating a tissue sample can include a tissue chamber, a liquid inlet channel, a liquid outlet channel, and at least one of components (1)-(3). The tissue chamber can be defined by a plurality of walls, at least one of which is transparent. The liquid inlet and outlet channels can be in fluid communication with the tissue chamber. Components (1)-(3) can include: (1) a deformable membrane disposed within the tissue chamber and being configured to oscillate, upon application of pressure thereto, to mechanically compress the tissue sample; (2) first and second electrodes disposed about the tissue chamber and being configured such that delivery of electrical energy thereto creates an electrical gradient across the tissue chamber; and (3) at least one deformable wall, which partially defines the tissue chamber and is configured to stretch either uniaxially or biaxially upon application of negative pressure to the tissue chamber.

Microfluidic devices, systems, and methods for evaluating tissue samples

This invention provides methods and devices for the high-throughput characterization of the mechanical properties of cells or particles. In certain embodiments the devices comprise a microfluidic channel comprising: an oscillating element on a first side of the channel; and a detecting element on a second side of the channel opposite the oscillating element, wherein the detecting element is configured to detect a force transmitted through a cell or microparticle by the oscillating element. In certain embodiments the devices comprise a microfluidic channel comprising an integrated oscillator and sensor element on one first side of the channel, wherein the sensor is configured to detect a force transmitted through a cell or microparticle by the oscillator.

Growing community of inventors

Columbus, OH, United States of America

David John Hoelzle