Custom Thermoresponsive Hydrogel Mat Manufacturing

About the project

Chemist / Polymer Engineer Needed to Fabricate Custom Hydrogel Mat PrototypeProject DescriptionI am looking for a freelance chemist, formulation chemist, or materials engineer to fabricate a custom, thermoresponsive composite hydrogel mat for an upcoming performance test.The mat utilizes a semi-interpenetrating polymer network (semi-IPN) consisting of Sodium Alginate and Poly(N-isopropylacrylamide) (PNIPAM), infused with Lithium Chloride salt.The freelancer will be responsible for sourcing the raw chemical materials, compounding the solution, casting/cross-linking the matrix, drying the final product, and shipping the completely dry, vacuum-sealed mat to my location.Required Formulation & Scaling MetricsThe mat must be formulated so that when I activate and fully saturate it during testing, it is capable of holding exactly 1.5 gallons (approx. 5.68 liters / 12.5 lbs) of water weight. To achieve this water-retention capacity, the baseline formulation must be scaled to the following quantities:Sodium Alginate Powder: 114 gramsPNIPAM Powder: 57 gramsLithium Chloride (LiCl): 568 gramsCalcium Chloride (CaCl₂): 284 gramsDistilled Water: ~2.3 gallons total across processing stagesCritical Physical Constraints & DimensionsMy testing chamber has strict maximum outer limits of 24" Long x 6" Wide x 6" Deep. The hydrogel mat will swell drastically as it hydrates. To ensure it fits perfectly after expansion and never exceeds these maximum chamber dimensions, you must use the following dimension targets:When Dry (Shipped State / Pre-Expansion): The product delivered to me must be 100% dehydrated, rigid, and thin (roughly 1 to 2 millimeters thick). Because hydrogels shrink significantly when dried, the dry dimensions should measure approximately 16 to 18 inches in Length and 4 to 4.5 inches in Width.When Fully Saturated (Maximum Expanded State): When I run the test and the mat absorbs the 1.5 gallons of water, it will expand to fill the bottom of my chamber, hitting a maximum expanded size of 24 inches (Length) x 6 inches (Width) x 2.4 inches (Thickness/Depth). This safely keeps the expanded depth below my 6-inch maximum limit, leaving clearance at the top.Step-by-Step Fabrication Instructions for FreelancerPolymer Dissolution: Dissolve 114g Sodium Alginate and 57g PNIPAM into 1.5 gallons of distilled water. Stir thoroughly (using a motorized mixer or immersion blender) and allow 12–24 hours to yield a completely clear, homogeneous, high-viscosity syrup.Casting & Cross-Linking: Cast the syrup into a flat mold. Treat with a cross-linking bath containing 284g of Calcium Chloride dissolved in 0.4 gallons of distilled water for 45 minutes to cure it into a solid, rubbery mat.Salt Infusion: Submerge the cross-linked mat into a salt bath containing 568g of Lithium Chloride dissolved in 0.4 gallons of distilled water. Soak for 12–18 hours to ensure full diffusion of the hygroscopic agent.Drying & Packaging: Dehydrate the mat under low heat (below 50°C / 122°F) until it transitions into a rigid, completely dry sheet measuring the required ~17" x 4.25" footprint. Crucial: The final dry mat must be vacuum-sealed immediately upon drying so it does not absorb ambient moisture during transit. It must arrive to me completely bone-dry.Estimated Costs (To Be Funded by Client)Raw Materials & Chemicals: ~$120 – $180 (Sourcing consumer/technical grade alginate and salts, plus a small batch of PNIPAM powder).Freelancer Labor (Estimated): ~$200 – $450 (Depending on experience, reflecting the 2-day processing and drying timeline).Shipping & Packaging: ~$20 – $40 (Vacuum packaging + standard parcel shipping).Total Budget Range: $340 – $670Freelancer RequirementsAccess to basic laboratory environment or workshop equipment (vessels, precise digital scale, mixing tools, vacuum sealer).Background in chemistry, materials science, polymer engineering, or custom compounding.Ability to provide photo updates at the mixing, curing, and drying stages. UPDATE : dimensions of matt is > New Cradle-Fit Mat: 12.5 { in} \times 5.5in \times 5.0 in= 343.75 in 1.49 gal full capacity.

Skills required