Blink.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Blink : MonoBehaviour
{
    SkinnedMeshRenderer rendererFace;
    [SerializeField]
    private AnimationCurve animationCurve;

    // Start is called before the first frame update
    void Start()
    {
        rendererFace = GetComponent<SkinnedMeshRenderer>();
    }

    // Update is called once per frame
    void Update()
    {
        if (Input.GetKeyDown(KeyCode.B))
        {
            StartCoroutine(Blink(0.3f));
        }
    }


    IEnumerator Blink(float duration)
    {
        float time = 0f;
        while (time <= duration)
        {
            time = time + Time.deltaTime;
            float percent = Mathf.Clamp01(time / duration);
            rendererFace.SetBlendShapeWeight(0, (animationCurve.Evaluate(percent) * 100));
            yield return null;
        }
    }
}