Dec.23, 2013

Conventional transplantable biomedical devices, such as pacemakers, defibrillators, cochlear implants, drug monitoring and delivery systems generally request sophisticated surgery which however often causes big trauma and serious pain to the patients.

Researchers at TsingHua University in China presented an alternative way of directly printing three-dimensional (3D) medical electronics inside the biological body through sequential injections of biocompatible packaging material and conductive liquid metal ink. According to the researchers, this method is based on a minimally invasive injection process which therefore will significantly relieve serious sufferings of the patients.

(a) Schematics for conventional surgery in implanting electrode for brain stimulator. (b) A liquid metal droplet on the tip of entry needle. An electric wire network (c), a node-shaped electronic component (d), and a 3-D triangle frame electronic component (e) and (f) fabricated by injecting the liquid metal into the packaging domains.

The researchers explain the procedure in details:

All the complex 3-D electronics is fabricated by using the clinical syringe as the injection tool. Firstly, fill a 10 ml syringe with 5 ml packaging material solution (mass fraction of 25.0%). And then vertically inject the solution into the target region at a rate of 1 ml/s. After removing the syringe, insert the syringe needle along the injection direction to shape a mold of electrode. About 3 ~ 5 min later, slowly remove the syringe needle and a three-dimensional packaging domain would be formed. Next, fill a 5 ml syringe with 2 ml GaInSn-based liquid metal ink and inject the ink into the electrode mold at a rate of 0.5 ml/s. Ultimately, an injected electrode can be fabricated. Using clinical syringe as the injection tool for fabricating complex 3-D object is the basic step of the present method. In fact, the size of the final object in the body can be either large or small, depending on the operation of the syringe needle and the injected amount/configuration of the liquid metal. All these difficult tasks request only a single or multiple injections.

Here, (1) denotes the formed packaging domain; (2) and (3) represent the fabrication process of electrode mode; (4) denotes the formed electrode within the packaging domain by injecting the GaInSn-based liquid metal ink.

Figure below: Visualization experiments to characterize injectable packaged electrode in a transparent pipette tip.

(a) The formed electrode in a 1 ml pipette tip. Schematics (b) and (c) are for electronic tests of the electrode. The input signal (e) and the measuring result (d).

Their research is published in Scientific Reports on "This technology increases general awareness of body electronics applications and 3D printing technology. Our experiements on lab animals such as rats and frogs demonstrate promising results." said researcher Liu Jing of the Institute of physical and chemical technology. But she said more research needs to be done before this technique being applied to clinical practice.



Posted in 3D Printing Technology



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alvaro wrote at 12/23/2013 6:08:08 PM:

Many lifes will be save !

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