https://civitai.com/models/20846/biomechanicals-hr-giger

Trained on 100 images in biomechanical style. Mostly paintings and illustrations, a few photos of props and some renderings.

Try this prompt as a start:

" style, hnsrdlf style, SUBJECT DESCRIPTION, intricate biomechanical detail"

I tried various models with this and got good results with: Analog Madness, Art & Eros, DreamShaper, ChilloutMix, Hassanblend1512, movieDiffusion, Elldreth's StolenDreams Mix, theAllysMix, LOFI, Timeless Diffusion and the original SD1.5 it is based on.

Note: some of the example images' prompts are from the img2img upscale, not the initial txt2img generation.