Novel Fabrication of 4D Printed Optical Probe Array with Nanometer Aperture and Optical Spot Size Tunning

Manufacturing an optical probe with nanometric aperture size and a tunable lens is one of the biggest challenges faced for near sub-wavelength imaging technologies. We report an arbitrary optical probe array by 4D printing with the drastically reduced nanometric aperture size. The array was fabricated by electroplating and the spot size tunning by a trapped liquid droplet. The initial structures were fabricated by two-photon 3D nanoprinting of Polydimethylsiloxane (PDMS) and metallization of nickel layer by sputtering to serve as a masking layer for guiding the transmitted light through the aperture and also to serve as a seed layer for electroplating to further reduce the aperture size down to 77 nm. Moreover, the optical probes filled with liquid droplet showed the optical spot size with light transmission could be doubled due to the lens effect from droplet. Finally untethered single optical probe was also able to be propelled by external rotating magnetic field thanks to the ferromagnetic layer which opens new applications such as biological manipulation.