An optical device that resembles a miniaturized lighthouse lens can make it easier to peer into Petri dishes and observe molecular-level details of biological processes, including cancer cell growth. The new microscope lens is also very cost-effective.
Many bioimaging techniques require fluorescent dyes to be added to specific cell targets. But a recently developed Stimulated Raman Scattering (SRS) method that uses a microscope lens, can avoid cumbersome labeling steps by using laser pulses to collect molecular vibrational signals from biological samples. The ability of SRS microscopes to produce high-resolution, noninvasive images at real-time speeds has prompted researchers to deploy them also for in vivo disease diagnostic studies.
One drawback of SRS microscopes, however, is that the detection system is affected by a background signal, known as cross-phase modulation, which is generated by the intense interactions between laser pulses and the samples. Researchers have created an ultrathin SRS microscopy lens using laser-based 3D printing. Taking their cue from the slender design of lighthouse lenses, the team printed tiny lens-like and mirror-like features into a transparent polymer only a fraction of a millimeter thick.