Magnetic resonance can provide rich structural and dynamic information on objects varying in size from small molecules (magnetic resonance spectroscopy) all the way up to the human body (magnetic resonance imaging, MRI). But while magnetic resonance is extremely sensitive to structural and dynamic changes, the detection of the NMR signal itself suffers from very low sensitivity: Typically only 1 in 10,000 spins is aligned with respect to the applied magnetic field, and hence the signal is 10,000 times smaller than it could be.
To address this most pressing problem of magnetic resonance, our group has invented bullet-DNP, in which nuclear spins are encapsulated in a bullet, and aligned almost fully using so-called dynamic nuclear polarization at low temperature. Subsequently the bullet is fired into an injection dock that rapidly melts the frozen spins, while largely retaining the spin alignment.
Bullet-DNP is a form of dissolution-dynamic nuclear polarization, but offers unique potential for scaling to small volumes and for increased throughput. Bullet-DNP also offers pathways to all-together new polarization schemes that rely on the rapid transfer of the hyperpolarized solid.
Another research area of our group is quantum-rotor-induced polarization. This somewhat intricate mechanism uses the large rotational splitting of freely rotating molecules or molecular moieties such as methyl groups to generate highly polarized nuclear spins. The most prominent quantum-rotor for such applications is para-hydrogen, which has widespread applications in magnetic resonance. Polar molecules such as fullerene-encapsulated water molecules or freely rotating methyl groups additionally provide an opportunity to probe and exploit the rotational energy structure with sensitive electrical probes.