Fig. 4. Examples of applications achieved by material removal using t-SPL.

a 3D nanofluidic rocking Brownian motor sorting device for nanoparticles patterned into PPA resist. Reprinted with permission from ref. ⁵⁶, AAAS. b Top: 32-level hologram in PPA, Bottom: a 300 nm deep sine wave used as master for UV nanoimprint. Reprinted with permission from ref. ³¹. c Gaussian-shaped optical microcavities patterned into PPA and etched into a Bragg mirror form photonic molecules. Adapted under CC BY 4.0 License from ref. ⁵⁴, Copyright 2017 Springer Nature. d Atomic scale memristor devices fabricated by etching a cone-shaped t-SPL indent from PPA into SiO₂. Adapted under CC BY 4.0 License from ref. ⁶⁵, Copyright 2019 Springer Nature. e Single-layer MoS₂ top gate transistor with record low contact resistance and on-off ratio. Reprinted with permission from ref. ⁶⁸, Copyright 2019 Springer Nature. f Selective removal of PPA for accessing a functional material to study nanoparticle assembly processes. Reproduced with permission from ref. ⁷², Copyright 2018 ACS. g Left: 14 nm half-pitch pattern etched into Si. Reproduced with permission from ref. ²⁹, Copyright 2017 ACS. Right: TEM image of a Si fin etched from patterned and Al₂O₃-infiltrated PPA resist. Adapted with permission from ref. ⁷⁵, Copyright 2018 ACS. h InAs nanowire transistor overlaid with t-SPL-patterned metal top gate electrodes. Reprinted with permission from refs. ^76,77, Copyright 2019 IEEE. i Integration of t-SPL with a laser writer for fabrication of Si-based room temperature single-electron transistors. Reproduced with permission from ref. ⁴³, Copyright 2018 IOP Publishing