  Humans rely on multimodal perception to form representations of the world.
This implies that environmental stimuli must remain consistent and predictable
throughout their journey to our sensory organs. When it comes to vision,
electromagnetic waves are minimally affected when passing through air or glass
treated for chromatic aberrations. Similar conclusions can be drawn for hearing
and acoustic waves. However, tools that propagate elastic waves to our
cutaneous afferents tend to color tactual perception due to parasitic
mechanical attributes such as resonances and inertia. These issues are often
overlooked, despite their critical importance for haptic devices that aim to
faithfully render or record tactile interactions. Here, we investigate how to
optimize this mechanical transmission with sandwich structures made from rigid,
lightweight carbon fiber sheets arranged around a 3D-printed lattice core.
Through a comprehensive parametric evaluation, we demonstrate that this design
paradigm provides superior haptic transparency. Drawing an analogy with
topology optimization, our solution approaches a foreseeable technological
limit. This novel medium offers a practical way to create high-fidelity haptic
interfaces, opening new avenues for research on tool-mediated interactions.
