The plaintiff has the burden of proof to demonstrate a safer alternative design by a preponderance of the evidence. Id. If no evidence is offered that a safer design existed, the product is not unreasonably dangerous as a matter of law. American Tobacco Co. v. Grinnell, 951 S.W.2d 420, 433 (Tex. 1997); Caterpillar, Inc., 911 S.W.2d at 384. To prove a safer alternative, the plaintiff has to show that the alternative design would have substantially reduced the risk of injury and would have been both economically and technologically feasible. General Motors Corp. v. Sanchez, 997 S.W.2d 584, 588 (Tex. 1999). Kindred v. Con/Chem, Inc. 650 S.W.2d 61 (Tex. 1983) addresses feasibility, Kindred held that a party may demonstrate that a safer design was feasible "with evidence that it was in actual use or was available at the time of manufacture." Id. at 62. Kindred did not distinguish, however, between the two types of feasibility, technological and economic, that are required to maintain a design defect cause of action under current law. Moreover, under the law in effect in 1983, either technological or economic feasibility was a permissible way to establish a safer alternative design, although not the only way. See id. (citing Boatland of Houston, Inc. v. Bailey, 609 S.W.2d 743, 746 (Tex. 1980)). Consequently, Kindred did not require the plaintiff to prove both the scientific and economic feasibility of the proposed alternative design, as Texas Civil Practice and Remedies Code section 82.005 requires today. See TEX. CIV. PRAC. & REM. CODE ANN. 82.005. Technological feasibility and economic feasibility are two different concepts that require separate proof. For example, it may be technologically feasible to install air bags on bicycles; i.e., scientists and engineers may have the ability to install air bags on bicycles. Having this technology does not mean that it is economically feasible, however, because installing air bags might cost hundreds or thousands of dollars per bicycle, thus rendering the cost of production unreasonable. In Robins v. Kroger Co., the plaintiffs sued the store where they had bought a cigarette lighter, claiming that the lighter was defectively designed because it did not incorporate a child-restraint feature. 982 S.W.2d at 158. The plaintiffs established technological feasibility through expert testimony that the relevant technology was available when the lighter was manufactured. Robins, 982 S.W.2d at 164. Independent of this evidence, the plaintiffs also provided expert testimony of economic feasibility by showing that the cost of incorporating this technology would approach $ 50 million or roughly 1 to 5 cents per lighter manufactured. Id.