Collagen is a protein of considerable scientific significance, as well as commercial interest, because of its unusual triple helical structure and its important biological functions. It is the major component of connective tissue including skin, bone and blood vessels. In addition to being a structural protein, it mediates platelet activation and the formation of hemostatic plugs. The large triple helical domains of collagen consist of three peptide strands of repeating Gly-X-Y triplet motifs, with Pro and Hyp principally occupying the X- and Y-positions, respectively. It has been reported that collagen related peptides (CRPs) consisting of more than ten repeats could activate platelets only if the peptides are cross-linked or displayed as dendrimers. The understanding of the structural requirements of CRPs for inducing platelet aggregation is facilitated by new synthetic approaches based on shorter peptide sequences. We have designed two collagen mimetic constructs using short, single stranded CRPs. The first one is based on the incorporation of self-assembling molecular pairs at both ends of the peptide, to obtain supramolecular collagen-like fibrils. The second approach consists of the attachment of the peptides to 200 nm latex nanoparticles, which allows a multimeric display of helical motifs. Both strategies generated functional biomaterials that induced the aggregation of human platelets with potency comparable to native Type I collagen.