Meanwhile, power delivery units connected to transdermal chargers can cause inflammation, and those powered by non-rechargeable batteries may need to be surgically replaced, which can cause complications, according to the article.
To address this gap, the researchers proposed a wireless implantable energy system with “simultaneously high energy storage performance and favored tissue interface properties,” as its soft and flexible design allows it to adapt to the shape of the tissues and organs.
The wireless power delivery device consists of a magnesium coil, which charges the device when an external transmitter coil is placed on the skin over the implant.
Supercapacitors store energy as electrical energy, compared to batteries that store it as chemical energy.
While supercapacitors store less energy per unit, they have a high power density and can therefore constantly discharge a large amount of energy, according to the article.
The prototype energy delivery system, contained in a flexible biodegradable chip-like implant, integrates energy harvesting and storage into a single device.
Power can pass through the circuit directly to a connected bioelectronic device, as well as to the supercapacitor where it is stored “to ensure constant and reliable power output” once charging is complete, according to the article.
A microrobot made by Hong Kong academics kills 99% of bacteria on medical implants
A microrobot made by Hong Kong academics kills 99% of bacteria on medical implants
Both zinc and magnesium are essential for the human body and the researchers note that the quantities contained in the device are below daily intake levels, making the soluble implants biocompatible.
The entire device is encapsulated in polymer and wax, which can bend and twist depending on the structure of the tissue in which it is placed.
Testing of the device on rats indicated that it can work effectively for up to 10 days and completely dissolves within two months.
According to the article, the length of time the device can operate can be modified by changing the thickness and chemistry of the encapsulation layer.
Drug delivery systems could be integrated into different tissues and organs of the body and “play a vital role in localized and on-demand drug delivery and therapy,” the paper states.
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Robot prototype 3D prints biomaterials inside the human body, reducing surgical risks
Robot prototype 3D prints biomaterials inside the human body, reducing surgical risks
To demonstrate the functionality of the power supply, the researchers connected stacked supercapacitors with a receiving coil and a biodegradable drug delivery device and implanted it in rats. The implanted prototype was not encapsulated in a single device, but rather had separately encapsulated parts attached together.
The researchers said there was still a problem with turning the device on and off as it only stopped when it ran out of power, but they said controlled activation of the charge could control the duration of the on and off.
In the rats that received the uncharged implant, the researchers said there was also some passive release of the drug, as the temperatures recorded in this group were also reduced compared to the control group.
However, the paper states that the prototype “represents an important step forward in the advancement of a wide range of transient implantable bioelectronic devices with their potential to provide effective and reliable energy solutions.”
