Moving Objects Without Touching Them
Modern science has discovered ways to move things without touching them. This was first done with so-called optical tweezers, which use light, and soon replicated with acoustic tweezers, which use sound.
Acoustic tweezers are of special interest because they can penetrate most materials. Their wide frequency range allows for the manipulation of items of various sizes, from individual cells to complex objects. They are also harmless to biological tissues.
For this reason, acoustic tweezers could have a wide range of applications, from surgery to drug delivery. The problem is that until now, precise control while using it was difficult in a complex environment like a living body.
This is changing, thanks to new discoveries published in Nature Physics by researchers at the EPFL (Switzerland) and the Vienna University of Technology (Austria).
Pushing With Sound Waves
The research team used a new method to create acoustic tweezers called “wave-momentum shaping”. The technique is the adaption to sound waves of a novel method using light to organize it despite a “messy” environment.
Essentially, it first “maps” the scattering effect of obstacles into a matrix structure (to the right below), allowing one to determine how to use the tweezers despite obstacles on the way.
This scattering matrix evolves in real-time as the object moves, and keeping it updated in real-time was one of the main achievements of the researchers, who used complex mathematical tools to do it.
Source: Nature
This changes the way acoustic tweezers work. Normally the method traps an object in one spot. Here instead, the sound waves gently push it along, like a hockey stick pushing a puck.
The method works with spherical objects, but also more complex shapes. It can also control rotations, adding more flexibility to the possible movements. It can work with virtually any material, with the target not needing to be magnetic or especially resistant.
Source: Nature
Possible Applications
Medical & Biotech
The possibility of direct therapeutic treatment throughout the body without surgery is pretty interesting. This could especially be used for cancer therapy, where delivery of the drug directly into the tumor could strongly boost efficiency.
“Some drug delivery methods already use soundwaves to release encapsulated drugs, so this technique is especially attractive for pushing a drug directly toward tumor cells”
Similarly, biological analysis and taking samples could be done without directly touching the tissues, reducing the risk of contamination or damage caused by the procedure.
Lastly, it could also be used for tissue engineering or even 3D bioprinting. Authorizing manipulation without having to cut through could help create more complex designs, bringing us one step closer to the dream of producing organs on demand.
Manufacturing
Moving at will in all directions, small particles sounds exactly what 3D printing is trying to achieve.
In that respect, acoustic tweezers could be a new method to add to existing additive manufacturing techniques, arranging the particles before they are bound together into a solid object.
It could also be used to assemble together separate parts, even when direct manipulation would not be possible.
Not A First?
We already cover a similar technology in our article “Acoustic Energy Emitters May Soon Eliminate the Need for Incision During Surgery”.
In it, we explained how another type of optical tweezers could achieve similar results. In that case, the focus was more on performing surgery without any cuts and moving small objects inside the body.
This was, however, more of a “classical” type of optical tweezer, locking the object in one spot.
In both cases, acoustic tweezers are making strong progress in their fundamental sciences, either for surgery with a real-time view through echography or with extremely precise pushing systems and up-to-date scattering matrix to keep the intended movement accurate.
So we should now get into the step where these technologies will be standardized and commercialized, helping push new innovative types of therapies and boost the efficiency of existing ones.
3D Manipulation Companies
While one of the most advanced robotic surgery systems is sold by Intuitive Surgical (ISRG), the company has less expertise in ultrasound or endoscopy than some of its competitors. So, it is likely that the first real-life medical application of acoustic tweezers might come from medical device companies already adept at integrating together many medical device systems like robots or surgery tools.
Alternatively, the progress in acoustic tweezers could benefit greatly from 3D printing and bioprinting, so a leading company in this sector might benefit as well.
1. Medtronic plc
Medtronic is a medical device leader, especially in surgery and intensive care. While the other segments could also be considered as afferent to it, the medical surgical segment of Medtronic represents $2.1B of revenues, out of a total of $7.7B.
Source: Medtronic
The company has been growing through organic growth, thanks to a large percentage of the R&D budget ($2.7B in 2022) and acquisitions (9 in 2022 and $3.3 worth of further acquisitions considered for 2023).
Medtronic sees a massive opportunity for simpler, low-cost robotic surgery:
“only 2% of surgeries around the world are held with the assistance of robots. There’s 98% out there that needs to be done via robotically-assisted surgery but not today because of the cost and utilization burdens”
It is with that strategy in mind that Medtronic has developed the Hugo system.
Source: Medtronic
It also sells the Mazor X Stealth spinal robot-assisted surgery device, thanks to its $1.7 billion acquisition of Mazor Robotics in December 2018.
Overall, the sterling reputation of Medtronics and its presence in virtually every hospital for at least some equipment gives it a good entry point to capture a solid part of the nascent robotic surgery market, either through internal development or acquisitions.
It also already sells endoscopic ultrasound systems, and its presence in cardiology could help apply the acoustic tweezer technology to cardiovascular therapies and surgeries.
2. Cyfuse Biomedical K.K.
The Japanese company was founded in 2010 and started selling 3D printers to researchers in 2013.
Its focus is producing tissues and organs without any artificial scaffolding, only the cells themselves, through its S-Spike platform. This is an ambitious goal, but also the final form of 3D bioprinting likely to be adopted over time.
The absence of scaffolding could prove crucial to producing “premium” organs as close as possible to native organs. The technology can only 3D print 2-3cm organ pieces at a time.
Source: Cyfuse Biomedical
It targets 4 segments: articulations, liver, nerve, and blood vessels. It could also be used to create “training” organs for surgeons, helping them learn without risking a patient”s life.
Source: Cyfuse Biomedical
Cyfuse is, for now, not profitable (after a brief period of profit in 2021) but is already registering a few million dollars in revenues.
This company is for patient investors, counting on this technology to become more mainstream and improve to the point where it can build full organs at once in one block.
In that respect, advanced acoustic tweezers might be missing steps to assemble more complex and large organs.