Context : The formation of planetesimals is often accredited to collisional sticking of dust grains .
The exact process is unknown , as collisions between larger aggregates tend to lead to fragmentation or bouncing rather than sticking .
Recent laboratory experiments have however made great progress in the understanding and mapping of the complex physics involved in dust collisions .

Aims : We want to study the possibility of planetesimal formation using the results from the latest laboratory experiments , particularly by including the fragmentation with mass transfer effect , which might lead to growth even at high impact velocities .

Methods : We present a new experimentally and physically motivated dust collision model capable of predicting the outcome of a collision between two particles of arbitrary masses and velocities .
The new model includes a natural description of cratering and mass transfer , and provides a smooth transition from equal- to different-sized collisions .
It is used together with a continuum dust-size evolution code which is both fast in terms of execution time and able to resolve the dust well at all sizes , allowing for all types of interactions to be studied without biases .

Results : We find that for the general dust population , bouncing collisions prevent the growth above millimeter-sizes .
However , if a small number of cm-sized particles are introduced , for example due to vertical mixing or radial drift , they can act as a catalyst and start to sweep up the smaller particles .
At a distance of 3 AU , 100-meter-sized bodies are formed on a timescale of 1 Myr .

Conclusions : Direct growth of planetesimals might be a possibility thanks to a combination of the existence of a bouncing barrier and the fragmentation with mass transfer effect .
The bouncing barrier is here even beneficial , as it prevents the growth of too many large particles that would otherwise only fragment among each other , and creates a reservoir of small particles that can be swept up by larger bodies .
However , for this process to work , a few seeds of cm in size or larger have to be introduced .