Existing attempts at wound-soldering rely on thermal imaging to measure temperature.
But that only measures the temperature at the surface of the solder, rather than throughout the material.
Mr Cipolato and Inge Herrmann, a chemical engineer at eth, hope their improved paste can get around such problems.
It is made up of two kinds of nanoparticles, specks of material of only about 20-billionths of a metre across.
Between them, these help direct the energy of the laser to the places it should be, and help doctors gauge the conditions in the paste.
The first set of particles are made of titanium nitrate.
They eagerly absorb photons of red or near infrared light, precisely the colours that most easily penetrate living tissue, and release the energy as heat to their surroundings.
That efficient absorption means the paste can be heated by a relatively weak laser beam, which helps protect the surrounding tissues.
Using such tiny particles is in itself not new.
But until recently most researchers used tiny rods of gold, which are expensive.
Nanoparticles of titanium nitrate, on the other hand, are easily and cheaply produced by spraying the right mix of precursor chemicals into a flame.
The second set of particles are a new development in the soldering world.
They are specks of a material which fluoresces.
In other words, it absorbs the laser light, but immediately re-emits the energy as light again, at a few very specific wavelengths.
Two of these wavelengths are also in the infrared and red colour range.
That allows some of the re-emitted light to emerge from the paste to where it can be analysed by an external instrument called a spectrometer.
By precisely measuring the difference between the two wavelengths, the temperature of particles that are emitting it -- and thus of the paste as a whole -- can be worked out.
Thus far, the researchers have tested the technique only on pieces of pig intestine that they obtained from a slaughterhouse.
Soldering a cut is done in a matter of minutes.
Similar “ex vivo” tests of the strength and permeability of the bond will also be needed for human tissue, followed by clinical tests on actual pigs and, eventually, humans.
But the researchers are optimistic.
At the conference, they were cagey about exactly what the fluorescing particles are made of.
They are applying for a patent, which could be quite valuable if the tools at the ready in a doctor’s office one day include a laser soldering gun.